The size small was extremely tight, but the length was right on. I am 5'3" and 125lbs. I only tried them on with underwear on, but you could see the underwear through the knickers. I was concerned it would not be long before they were worn to the point that I was showing the infamous crack during a ride.
The chamois is wide, thick and dense in the rear, but less so in the front. I ride about 5 days a week, a 1-3 hours each day and for me the chamois felt more like a diaper, much too thick.
Long story short, I'm not hard to please, but I had to send these back. They just did not fit well and given the chamois, I didn't think a size larger would help.