I used the esx24 mkII for a while...I couldn't get shit out of it. Too powerful to be any good to me. It just did too much stuff, and i've never been anygood at the sampler/sample game. I'd much rather synthesis everything.
I been using an elektron machinedrum for drums and I LOVE IT!. but anyone who's new to the game might not want to through down the bills for an elektron OR 909.
There are plenty of Audio Unit freebees on the web for drum synthesis.
regarding the hardware/software issue. I say hardware for sounds, software for processing/arranging...simple!