I bought 2 of those for my studio, I'm not a real drummer but I have put some time into it and I'm pretty good for "not a drummer".
So, when I installed the beater to test it against my typical felt beater I noticed a weight change, but it was more of a general slower reaction time particularly when leaving my foot off the pedal, so I think my old pedal spring is ready to retire.
Now the sound...wow....
It does make you hit it a bit harder (which adds a lot of "umph") but it generally boosted the attack and depth of my 22" concert bass drum making it sound like a lower tuned 24".
I do have a very weird bass drum setup but I think that beater will make most bass drums punchier, heavier and louder, just make sure you place it in the right height and with maybe a stiffer spring.
