Oddly, just yesterday I took 32 Gatorskins off my bike a built up Disc Trucker.
Bought and rode them for a brevet. I finished, but an hour late. Kept them on for 502 miles total miles since 4/8.
They were nice, quiet. But, nowhere near the traction I was used to on the 38 Marathon's, a 420 on the front and a plus on the rear. I just put back on, especially in the wet and on the random cruft one faces on the road. They were a lot lighter. All objective measures they should be much faster. I really didn't notice it, perhaps on the next ride (first since switching back)...
1 flat in the 502 miles... I pinch tested the tire pressure before riding, but got a pinch flat sprinting up my pea gravel driveway. I'm 265, and was running about a 20 lb pack.