Dave used a Roland Mini-cube to amp his Martin B-1E acoustic-electric bass and it worked well whether on stage, in a jam or just practicing at home. The only problem he ever had with it was it didn't give much notice when the batteries were about to go out. We were in the middle of a jam one evening at a festival and he was doing his bass rhythm (the only bass in the group) and suddenly there was no sound. The batteries just died in the middle of a song. Luckily, he had new ones handy and only missed one song while changing batteries.
I have a Roland Cube Street (not the EX...) and it works very well. I've used it for smaller gigs as a PA. It has a separate mic channel, built in effects, is quite loud and batteries last a long time between being changed.
I've never seen a Roland "Mini-cube", but their Micro-cube series are too small to create enough sound other than the smallest venues.