Bike Rumor reported on these yesterday. http://www.bikerumor.com/2012/09/20/int ... ent-157111
I've owned a pair for the past 11 months. Not only are they insanely light (150g for a size 12), but the stiff upper gives the shoe an insanely efficient power transfer. Heat has never been an issue. Durability is great. 11 months of daily riding/racing and they still look brand new.
My 5 second, 15 second, 30 second, and 1 minute power were up about 6%the first day I switched from my Mavics.
The price is steep compared to other shoes, but honestly, these are nothing like other shoes. Bonts, rocket 7s, etc do not have the stiff upper, and that makes a huge difference for your sprint power.
If I had to choose between giving up my zipp firecrests or these shoes, my zipps would be gone in a heartbeat. If I had to choose between racing my caad10 with these shoes vs an S-works McLaren in "normal" shoes, I wouldn't think twice about choosing the shoes. I've ridden a lot of different bikes (storck, specialized, trek, cervelo, etc), but I've never gotten on a bike and thought "holy crap...I need this" like I did when I first put on the shoes.