I've been looking at the m2n-e for a little while and haven't found any actual reviews, mind you I haven't really looked that hard. Just doing a quick check of google, the first 4 pages don't have any reviews from anyone other than customer reviews. I read 100+ customer reviews on places like newegg and ncix and they all say that it's a solid preformer, but it absolutely needs a bios update or it will crash, lots. Also they said that they didn't like the fact that it doesn't have any firewire ports, but it doesn't matter too much for me since I don't have anything that uses firewire.
One thing you'll want to make sure is that you get a case that can somehow get air over that passive heatsink, otherwise it'll get pretty hot. Just trying to think offhand about it, I think the Antec Sonata II or the Antec P180/P180B could do well with it, since they both have 120 mm exhaust fans right behind where the heatsink is... at least I think, wait, just checked, never mind... I think. Just forget about what I said.
The one thing that's stopping me from buying this motherboard is I've heard that only some motherboards allow you to override the automatic CPU/RAM divider. I know that 590 chipset allows you to do this, but the board that has it is somewhere in the realms of 150 bucks more than the m2n-e. If anyone can confirm or deny that this board can overclock without the ram divider being changed, that'd be cool.