I'm 6' w/ 35" inseam, 175lbs bare w/ 31" waist.
I did size medium and they're rather snug on my thighs (but I like the compression). Straps fit my shoulders just right but the leg length is off. Seems like my legs are too long and the bottoms ride up to just below my knees at the thinnest part of my upper leg and they gap a bit. Perhaps I should have tried these in a large, but in doing so it seems the crotch would be a problem as I use these for MTB too and need to worry about saddle snag.
They are windproof, that's for sure and that's exactly what I wanted/needed so they do get the job done.
Be warned: I thought my seatpost was bending or my frame was in trouble when I first rode this on MTB - the pad is VERY thick and creates an interesting feeling when on the saddle. I'm normally riding thinner seat pads for better saddle feel, this one will not allow the best feedback from your bike, it'll mute the feedback and like others may agree, this is not always best.
FIT: not quite European, not quite American so maybe buy your normal US size and 1 size larger then return the least favorite.