Awesome piece of kit
I use this mainly for triggering midi (through Ableton and Battery). It works great, reliable, solid build. Some people find the top pads unresponsive but they are designed to be hit from the top as opposed to from the front.
Great built in effects, looping facilities, software is really simple too (once you have the correct sample rate for your samples). Presets for external acoustic triggering are great, pretty much plug and play and then adjust sensitivity or whatever according to your playing style.
Great as a stand alone unit or as a midi trigger. Really adds to the scope of what you can do live (especially with Ableton)