DMP-2 doesn't kick out quite enough phantom power when running two condensers, simultaneously. This is only going to be a problem, by the way, with some mics (most condensers, actually, will be fine).
It also doesn't have any means of padding the input the way the DMP-3 does, so on very loud sources, you're either going to need a mic with a pad, or you may have to purchase some of the Shure attenuators (something you should have anyway).
Other than that, they're mostly the same.
