While a little stiff during break-in, this is a very high quality biking shoe for open pedals. I've worn them about 10 times and love them more as I go. They are heavily constructed, but not heavy to wear. The stiff sole and unique composition denies any slippage on a pedal even when standing up and going full bore. These have exceeded my expectations.
Great fit and super comfortable!!
And for those of you who have not bought a new pair of 510s in a while - you will be amazed at how much better a brand new pair of soles attaches you to your bike!!
Huge improvement in grip!
My old shoes were three years old and still in great shape but the soles are nowhere as grippy as these are.