Last year I got smalls (the ones I think are performers) and they were a bit too big - couldn't keep my knee warmers up kind of baggy....
So this year I went for the xsmalls (pretty sure these are power shorts) and they are skin tight
could just be the difference in the cut, but its good I prefer a bit more form fitting.. their size chart says a xs is a 2-4 and I'm pretty small so I'm usually on the lower end of that.