I don't own these wheels but I've ridden them in some TT's this year. The set I rode was a custom build with PT SLC+ rear hub. These wheels feel fantastic! They roll extremely smooth and feel stiff. I did go pretty fast on them, the first time I rode them this year I set a PR that ended up being my 2nd best time of the year (28:30-something in a 20k) of the year. I could definitely feel their lightness compared to my regular DT1.2 rims with PT Pro+ rear hub. They spun up fast and seemed to take a little less power to hold at speed even though there are more aero wheels out there. They impressed me similar to my first ride on 404 tubulars.