Being named R1 knit road shoes, I was expecting a very soft upper (slipper like) with a nice stiff sole. The Knit upper is much more supportive than I was expecting and still very comfortable for my feet with massive air flow. The shoes have large air ports on the sole and on an early morning spring ride my feet were very cold. They are perfect for here in Southern California during the summer. Be careful on the sizing. I wear a 9.5 US shoe, a 43.5 Sidi, a 43.5 Shimano. The Fizik size chart said I should wear a 42.5.
So I ordered a 43 - Wrong, I was swimming. Went to a 42 and they fit very nicely. Be careful once you mount cleats they will not take them back (anyone need a 43?).
I wanted to love these shoes. I have a Mt Bike version of this shoe and it is great. Maybe it is my cleat design difference (LOOK vs Shimano) that causes the issue, but my feet still get hot and tired in these shoes. I love the ratchet design and durability and maybe it is just my sensitive feet, but it did not produce a cooler foot.
Living in the deep South of the US, I know hot weather, and this shoe is made to help keep your feet cool. Plenty of ventilation, but even with the knit construction they are very stiff and fit me similar to the Sidi shoes that I have used for years.