Hey Ric,
I had one. Dunno if mine was defective, but it was VERY low volume. Maybe on the floor and against a wall, it could cover something - but I don't know what other than solo bass guitar practice (4 string that is). Again, could have been me or the unit, but I didn't get much out of it. Maybe they'll send me a new unit and I can try again. Now - the Minimark, that's a whole nuther animal. This thing has more output than many of the competing combos on the market - and a very fine sound. It also works great with slave cabinets and PA systems. And the briefcase profile makes it seem LIGHTER than its listed weight. The only downside is the piezo tweeter can not be easily turned off. That tweeter, in certain situations, like with DB, can be harsh. In other situations, like electric bass on rock music, it might help the sound cut through. I've heard a rumor that it can be disconnected, but I don't know details. Given the choice of Micro or Mini, I vote Mini - it's just so much more capable, and the size/weight upgrade is really not much.