i have one. it currently hum's really bad (need to check grounding). it's an early digital fx processor. the distortion is a bit sterile. the presets are a bit heavy & need to be be dialed back a bit. it's a huge pallate & you can make some funky sounds with it, so if that's worth $50 to you then by all means jump on it.
for bass, i did a nice impression of Screw by The Cure with it.
The Cure - Screw (Peel Session) - YouTube