Cheffywrote a review of New Balance MO80 Minimus Running Shoe - Men's on April 11, 2013
Familiarity: I've used it once or twice and have initial impressions
The fit of the last (foot shape) is identical to the MT10. The upper has a bit of room in the toes but is a stiffer mesh that has less give than the mesh of the MT10, designed to keep out dust/sand and protect from puddles. It tends to fold and bunch up a little around the flex point for me but it will probably soften with use. The tongue is not gusseted and I found it easily twisted and folded when putting the foot in.
Length is true to size barefoot or with a thin sock. However, I found the toe-room a bit lacking compared to the MT10 due to the stiffer upper, and even a wide (2EE) in my size allowed my 4th and 5th toes rubbed the end. In the end I needed to go up a half size to the 11D in the MO80 to accomodate my wide toe splay, even though the shoe was a tad long for me.
The MO80 has good forefoot flex but is definitely much stiffer then the MT10 (particularly in the mid-foot and heel), though not as stiff as the MT110. The midsole is a beefed up MT10 with amazing toothy tread. It is a bit less cushioned than the MT110, especially in the forefoot. The vibram outsole is soft and will probably wear fast on rock and asphalt but is great for trails. The lugs will probably make it uncomfortable on paved roads anyway.
Lastly - there is a pronounced arch support in these compared to the MT10. That might be a good or bad thing depending on your needs. True minimalists will probably find it far too much, while bad over-pronators like myself transitioning to minimalist running will appreciate the support. I couldn't keep the MT110s due to lack of any arch support and the raised lateral edge increasing my over-pronation.
Overall a good shoe, but I wish it had a little more midsole in the forefoot. The level of midsole support is a bit light for people transitioning or logging a lot of hard miles on technical terrain, and the stiffer heel/midfoot and arch support might encourage a heel strike in those still learning proper barefoot form.