This is normally one of my favorite brands, but I will probably end up returning these, both sizes.
I'm about a 35 waist, I generally wear size L; but in this case, they were huge, like they accidentally mislabeled a batch of XL. I tried ordering size M instead; they're just a little tight but I could live with that. I think they'd be perfect for a 33-34 waist.
As someone else mentioned, they are very thin, nearly see-through; if they didn't have a double layer in the front panel, they'd be see-through as well. I'm sure that's great for air flow, but I'm not sure how long they will last.