I recently ordered a pair of these, the v1, real cheap from 6pm.com. I ordered them a half size up from my usual size to make sure they could accommodate socks.
When I tried them on, they seemed to be kind of unstable. Just standing in them, it seemed like my feet just immediately went into a pronated position, and walking around the house they seemed like they were rolling in too much during the stride and were kind of rocking whenever my heel hit the ground. I don't know what they'd be like to run in, but I don't really want to chance it. By contrast, I have a pair of MT10v1's that I wear as everyday shoes (never ran in them) that are rock solid to stand in and walk in.
So, I'm wondering if anyone else has experienced the same thing in the MR20's, either version, or any of the other NB Minimus shoes. I think the larger size (a little too large) didn't help things, but it seemed like the construction might be to blame too. I'd like to try the MR10 or 00, but I'm not sure after this experience. The 730's look promising since they seem to have a flatter sole.