I've owned the markbass 2x10 combo for about 5 years, great volume, functional and really portable. I traded my giant ampeg rig for it b/c i needed something light-weight but still loud enough for practice and gigging - this combo was perfect for that.
I like that the amp has only a few knobs-it's no fun having to screw around with dozens of dials and buttons to find your tone. Very minimalistic, yet effective: I usually leave all my EQ knobs Zeroed out and just play with the VLE & VLX voicing knobs to dial in a good tone.
at live shows and in the studio, the direct XLR line out is awesome for plugging straight into the PA or mix board. One complaint is that there is no mute button but whatever, I'll live.
sure, there are lots of high dollar tube rigs out there that weigh 1,000's of lbs and give you better tone, but I'm poor and those don't fit into the backseat of my Kia.
if i had unlimited $$ at my disposal, i'd prob trade my Mark for something like a Trace or an Ashdown and hire a gorilla-man to carry it around for me.
here's a picture of my most current rig. I've noticed that markbass made a small change to the head unit on this combo a couple of years ago, added another volume or something? anyway, the new ones look a little different from my older model, but still the same output, 300W at 8ohms, 500W at 4ohms. I think it would sound a lot better if I added a 1x15" cabinet to round out the tone.
If you're thinking about buying one of these, try finding something USEDthe price they charge for these at GC is absurd. Mine has been through a lot of abuse over the last 5 years and i haven't had a single problem, so i'm willing to bet their used stuff is pretty solid