I'm sure the Roland is better, but it's also 4 times as expensive....
"Black Jak, just wondering if you can tell me something about the Yamaha d55. I know it accepts two pedals, for bass and hi-hat, which makes for a full-kit feel, right?"
That is correct. It's a full kit in terms of available sounds, and the sounds are very good, but it obviously doesn't have the feel of a real kit at all. That's the only disadvantage I have found. I'm thinking of selling mine and buying a real kit. The only reason I haven't is because the sound of the 55 is very good and it takes up no space in the studio. I'd rather have a real kit, but for the money the 55 is so much better than the other alternatives in my opinion.
"But how do the cymbals work? How can you move from a ride cymbal to a crash? Is it a touch-sensitive thing, or simply not possible?"
They are touch sensitive. Hit it soft, it sounds soft. Smack it hard and you get a loud crash. It's very much a digital kit within a small footprint. I'll try to post a link to a recording I've made with it. I'm not a drummer, but this thing gets the job done much better than the SR16. Take that thing out of your vocabulary ASAP!
One other thing....
The hand percussion is very good also. If you want some bongos, they are in there. Great for acoustic stuff. I'm just very pleased with the whole thing. It looks like a toy, but it honestly does not sound like one at all.