I use a Roland SPD-S in my band,*You can see it in my avatar below my mac* triggering various loops, although I tend to set the pads up to play through, rather than having to keep triggering the pads myself. So its much like an on/off for the loop.
I don't tend to use it much for percussion sounds, and frankly in my opinion most of the preset sounds are pretty lame.
I also add a Roland V Drum pad on it for odd snare sounds.
Overall for me , its a really important bit of kit for what I do.
However, its an expensive bit of kit, and I doubt, if I did not need it I would buy it.
Could get a new couple of cymbals with that money!
And if you're looking at it for home use, you'll probably want some kind of monitor....here come the extras!
I think the Roland SPD20 may be more suited to pure percussion sounds rather than the SPDS which is more for triggering?
Has anyone seen the new Yamaha DTX-MULTI12.
Looks quite cool!