The Markbass Micromark is, bar none, the most efficient, lightweight, combo amplifier I have played through. I purchased one new in 2007 and used it until 2004 almost exclusively, mostly for small gigs with acoustic piano, drums, and upright bass, but also for gigs requiring backline (bar gigs, some theatre work). It can't compete with a loud drummer or a guitarist with a tube amp who insists on turning it up for 'tone', but if you're playing with real musicians who know how to control their dynamics, it's pretty great for its size.
I don't use it anymore, but keep it as a backup. I love acoustic tone, and sometimes it was great for augmenting my acoustic sound on upright bass at a very low volume, but I realized as time went by that the low-end tone I wanted to project wasn't translating through the speaker, and it was inherent to the design. The Minimark 802 is a lot bigger in size, but it is also considerably clearer, and moves way more air.
To compensate for the lack of low end EQ, I always packed the fdeck HPF-pre for every gig with the Micromark, and still do with the Minimark 802. (I actually attach it with velcro to the top of the amp)