I think it's a very good piece of gear. I had the MB2 for absolute ages and loved it. I wanted to have the smallest board I could get away with, so I needed to hoof the tuner and compressor. The MB3 delivers well enough for me to not miss anything I've taken off.
* studio quality DI. 2 of them. Silent as a church mouse
* compressor does what I need it to do. It's not magical, it's just good. It's pretty much the compressor from the EBS heads
* tuner works really well I think. Well enough to track as accurately as my TC Electronic clip on and as well as the BOSS TU-2 I took off
* The EQ is fabulous I think. I have mine barely on, mostly for taming the upper frequencies, but it covers it all
* The drive is a bit of a mission to get right, probably, for me, because I've never used drives much until very recently, but with its own EQ, and the ability to either run the drive on its own, or, on top of the clean channel, you can get lots of very usable options
* FX loop, which was essential to me
I've read many reviews on it, some glowing, some scathing (mostly on the bleh drive, average compressor and iffy tuner), but if you're looking for an option to go bare bones, this'll do just fine. In addition to a compressor and tuner, then same - just fine.
Hope that helps mate