Just picked this up last week and have begun fiddling with it. Can be used with either bass or guitar. My hope is it will replace my GT Pro, GR-33, Ground Control Pro, and Variax. It's basically a much improved GR-20 + a VB99/VG99 in one, though obviously not as deep since Roland still needs to sell those products too. The Industrial Radio Bass that Sly has is still the best tracking/low latency bass product on the market, but I can comfortably say that this unit is the best pitch-to-midi synth Roland has made for bass yet. The tracking is still a bit slow on lowest strings, but with my piccolo-strung bass it's super fast and compares favorably to Axon's units but with the glitchiness and false triggering. Featuring on board COSM bass/guitar models (P bass, J, Stingray, Rick, Thunderbird, Hofner, etc), COSM amps, dozens of effects, and 2 independent PCM-based synth modules with ove3r 910 sounds as well as on board mp3 player and looper means you can be your own one man band. There's some sound/video samples here:
http://www.roland.com/GK/GR-55.htmlHere's some samples posted from a fellow bassist showing examples of the COSM sounds:
http://cgraham.com/chris/music/bass/gr-55/
