Tims issues sounds like a very common one. It's not the key action. 9 times out of 10 it's because the player hasn't built up the finger strength needed for fully weighted keys. I see players pull off amzazingly fast runs.., and triggering multiple velocity switches on fully weighted key with no problems. I see keyboard drummers playing very intense drums on fully weighted keys. It can be done..., you just have to build up the finger strength to do it.

It took me a while to adjust to my MO8 when I had it. I'd been playing synth action for so long my fingers were pretty weak on a weighted keybed. Didn't take too long to adjust though.