I've had the SPDS for about 2 1/2 years now. It COMPLETELY changed the way I play drums. I've also been doing a solo entitled "The Explosion Group" show lately triggering loops live and such (listed below is my rig). Some quick observations on my use of the pad...
Very soon after I bought it I noticed one of the pads not triggering correctly, and actually being triggered from other pads. Honestly I was too in love with the piece to send it in for repair...so I just held on and worked around it. Nearly 3 years later the problem hasn't gotten any worse, and I still LOVE the piece.
A few limitations I've found with my new setup:
-With 44khz samples you really can't play more than three pads at a time or the sample playback gets funny (especially loops). I don't remember if this has always been the case, but I'm pretty sure.
-The display makes it a bit tough to level match samples that you're recording.
My current set up:
Ayotte custom drums (16x18 bd, 14x14), 1963 Premier 5 1/2"x14 snare, 20" KZildjian Medium Ride, mid-60's 14" Zildjian hihats, wurlitzer 200 electric piano (with some pedals through a fender 68 deluxe reissue), Roland Juno 60 (with some pedals through a fender pro junior), Roland SPDS, and tons of percussion stuff.........
“PROGRESSION: Music Software for Guitar, Bass, Keyboards, AND Drums”