Boss GT-1000CORE

I've now had this for a year, upgrading from GT-8, so I already has some understanding of how Boss processors work, since there definitely is a slight leaning curve. My setup is Guitar -> GT1000C -> Engl E530 in fx loop-> GT1000C -> Harley Benton GPA-100 -> Marshall 2x12 with WGS Veteran 30 and Jensen Electric Lightning.

Upsides:
-Converters seem great, compared to GT-8, there's a lot more clarity. Latency is almost nothing, supposedly less than 1ms according to Leo Gibson's test on youtube, which is faster than other processors of it's time. FX loop doesn't seem to affect the tone.
-Alot of processing power, you can have all 24 blocks on at the same time. Majority of blocks are locked into certain effect type (not specific effect model, just the type), but they are likely something you would use anyway, so you shouldn't end up lacking. Blocks can be placed anywhere, assigned to go on and off with switches, picking dynamics or wave forms. There 3 dividers to create paths and parallel routes.
-Patch changes are instant and delay/reverb trails carry on.
-6in-6out audio interface helps in direct recording alot, you can record dry and wet tracks simultaneously, and later on reamp the dry signal without separate reamp box.
-IO options: Stereo in. 2 Effect loops, of which 2nd can be used as sub out. 2 Control outs, which can be used for expression pedal, more switches or to control amp. I use the switches on the unit to control effects like manual mode, and self made switch pedal to cycle patches up and down. If you need XLR out, you probably want to look into full GT-1000.
-While I don't really use amp sims, the newer AIRD ones seem pretty good, the feel is very good. A gripe some people have is that the amps are Boss's own concoctions, so you don't really find models of some specific amps in here, but in the end, it should be about having good tone rather than specific gear. Juggernaut and X-modded especially were to my taste, but more of the later in downsides...
-Effects sound great to my ears. Unfortunately I can't say how they compare to similiar products.

Downsides:
-While there is 4 EQ blocks, parametric EQ only has 4 bands per block, and 2 of those are high and low shelf, leaving you with just 2 adjustable bands. This is something that already was in GT-8 and I think they should have added multiple bands by now. While you can just use multiple blocks after each other, it feels bit silly and takes up EQ blocks you might need elsewhere. Graphic EQ has lot of bands, but of course those are fixed so they don't give you the control that parametric does. But then again, it's best not to get too carried away with EQ...
-Cab sims can't be used without amp sim, atleast thru main out. I don't know does this affect uploaded IRs since I haven't tried them, but this is kinda odd decision on Boss' part, likely due to them wanting make amp and cab blocks somehow interact with each other? This can however be circumvented by either adding amp into a divider path and setting the volume to 0% on that branch, but it costs one divider, or using transparent amp somewhere in the chain, but this colors the tone abit.
-I can understand all blocks being present in a patch, but it's a bit messy.
-Of the amp sims I particularly liked X-Modded. Unfortunately for some reason it has weird phasing to the sound when which makes it unusable. I dunno is something wrong with my unit or did an update somehow mess up this amp because it did work fine previously. EDIT: Problem was in AIRD output select being set to record, which seems to act kinda funky.

I was searching for an all in one modeller for guitar and bass since 2021. After 2 years of extensive youtube videos, forum crawling and internet text reviews I settled for the GT1K core. I play guitar and bass and needed an all in one compact solution (for the time being) as I do not own any amps or any pedals. I have been using Helix Native since 1 year, including for rehearsals through audio interface and MIDI foot controller with my band.

First impression: out of the box after adjusting the input level for both of my electric instruments the sounds are very much useable. I did not have to struggle for weeks and weeks on end like I had to do with Helix Native and the sounds are just as good if not better. As this is only after 48 hours I am still choosing my words carefully but initial impressions are very positive. I wont talk about cosmetic appearance and build quality, it is very decent. I do not think it will break soon as Boss products have good reputation.

Now comparing to patches I made from scratch: I had to watch few videos to get used to the layout, how assigns work etc etc. But I had been doing my homework before I received the unit in mail so I knew what to expect. People say "oh it is so intimidating Boss UI is so difficult to navigate" that is NONSENSE because like EVERYTHING in this world, there is a learning curve. Yes it may not be for everybody but show it the love it deserves and you will get the same love back in terms of sonic results. Everything about this exudes quality EXCEPT the micro USB B type USB input jack. I had to by a separate cable for EUR 36 and I am quite mad about it.

I spent hours separately with my electric (Charvel San Dimas style 1 HS HT with Seymour Duncan JB) and Tobias Toby Deluxe IV Jazz bass and have made my tones in less than a day compared to weeks/months with Helix native. I actually purchased the GT1K because after a year of using HX native and being frustrated with it constantly. I even purchased 3rd party IRs, preset packs from famous youtubers and it was just lifeless. This GT1K on the other hand is definitely an upgrade ONLY in terms of saving time. As far as tones are concerned, I am hearing different "modelling flavor" but the fidelity of GT1K core is higher (probably due to 32 bits AD/DA)

Here is something for bass players as I have seen ZERO reviews for this device for bass only:
I got to almost 80% of Justin Chancellor's (Tool) tone in literally a day. What else do I need to say? This is without 3rd party IRs, no purchased preset packs. The bass effects are amazing and the bass amps are very well, round, full bodied and just punchy. The pick attack feels like you are playing through an amp. Of course my comparison is with Helix Native and I have to say I am very happy I got the GT1K core. Bass effects are supreme quality, pitch bend effects have no weird artifacts and bass wah is MORE useful than any wah model in Helix. I have made a pretty complicated chain with only 4 assigns (3 from 3 footswitches and one from expression pedal heel down as tuner, I am using Boss EV-30. Great pedal works immediately after connecting.)

I will update this review after 6 months. For now I can definitely say this thing is amazing. I will now build a small pedalboard around it.

UPDATE 26-05-2023:

So here are some more finer updates:

1) Guitar: No complaints. I love this. It does everything I want and more. The feel, response to picking and playing dynamics is superior to any modelling technology I have used (including NDSP, STL Tones, Helix Native etc.) As tone is preferential, for my kind of tones it does a great job.

2) Bass: I have been struggling to achieve a tone I am 100% satisfied with. More specifically I have a problem with the X-bass compressor. I am not able to dial it in, but I guess I need to spend more time on learning how to do this. I have made tones from scratch and each iteration introduces a small variable in the way I dial tones, but the end results vary HUGELY. So there are both pros and cons to this, pros being that I SEE that this unit has potential to have a HUGE variation in any tones you want to make, but the con is that with my bass (I think it is the fault of my bass) is shi**y and maybe with a better bass it might be a bit different. In a nutshell, my problem is the lower end being "boomy" and "sub-woofer-ey" . There is also a hissing noise in all bass patches I make using the Bass Drv effect, however my bass (Epiphone Tobias Toby Deluxe IV) is notorious for having hissy and cheap electronics, so I am wary to blame the GT1KC for this problem.

The insight from this is (IN MY EXPERIENCE): the quality of your guitar/bass and the electronics play a HUGE role in the output quality. It gives the impression of how clear and transparent the converters are. If you use a good quality guitar bass with good quality components and electronics, you will really hear each detail. I am seeing a huge difference between my guitar and bass, and it has made me realise it is time to upgrade the bass :D

Effects: World class.

Durability: world class, buttons are amazing

Flexibility: Spend some time to learn how the UI works. You can re-route things like crazy. You can also see paths in stock patches to understand this.

I have the GTKCore for a few months and I really enjoy it. Stock tones and the patches available from Boss/Roland website and dedicated FB group give plenty of good effects to start with. The unit has a lof of options and possibilities, so you really need to invest some time in learning how to operate it. That is in case you want to explore and create your own tones. I'm mainly an attic player using headphones. The stereo possibilities give awesome tones. The unit isn't cheap, but the quality, useability and versatility is on parr with other brand units costing twice the amount. I had a previous generation processor from another brand before and found the tones too digital/artificial, so I sold it after some time. The Boss unit is much much better and I'm sure I'll keep it for a long time to come.

Iv'e only had the unit for a few weeks but I am very impressed by the build quality and the many features. If your new to this type of equipment it can be a bit daunting to get familiar with how to manipulate the controls, but there are plenty of videos on YouTube to help and you can download the User Manual and Parameter Guide from the Boss website.
However, my main reason for writing the review is to inform other customers in the UK about the additional costs you will have to pay when importing this item from Germany. In my case I had to pay a total of £114.39, comprising £102.89 for VAT and Customs duty, plus £11.50 for UPS delivery and handling.