I've had successful long runs (10-13 milers) in them wearing socks at a sub 7:30 pace for all runs. They're light and comfortable with no issues initially.
Here are my nits:
1) They're about .25 of a size too big. All of my shoes are 11.5, but in these I should wear an 11.
2) My feet sweat and despite the lack of seams - my feet got hot and wet and I got massive blisters today doing an 8-9 mile run around 6:30-7:10 pace. The blisters were so bad I had to walk the last 1.5 miles. They were the size of a 50 cent piece (which for those of you under 30, a 50 cent piece is something you could be sure your grandparents would give you because you typically had to go to the bank to get them special. Grandparents have little to do, so they go INTO the bank to get these. They (the 50 cent pieces) are not gangster rappers, it's a currency -which means it's money bigger (size) than a quarter.)
3) blisters running in them with no socks, even my Brooks can get me 8 miles with socks or blisters.
4) racing flats should not be $130. A decent dinner yes, but sub-9 oz shoes, no.
5) there's a lot of heel for racing flats for people who heel strike, those people probably don't run fast enough to need these (do they?)
Here's what I LOVE about them:
1) The high heel and toungue along with some tacky coating on them make them VERY easy to get on
2) the laces can easily be snugged up or loosened and they don't slip, the lace lock works awesome
3) they feel great with a very thin sock
4) I'm guessing chicks dig them.
PS - why would a triathlete have to train with a butterfly stroke?
I raced a triathlon with these shoes with 4 mile run and these shoes performed much better. The run was a trail run with limited pavement - it was essentially an Xterra off-road run. No blistering and my T2 was incredibly fast - no fumbling with a tongue or laces. I was much happier with these shoes on the short course. I'll be racing again in them again with a 5 mile run in 2 weeks.
Here's another review I found from inside tri: http://www.insidetri.com/article/71114/zoot-ultra-tempo%2B