I have some xl ronin pants (last years) and an xl aeryx suit from last year and after trying them on back to back I'd say that the ronin pants are maybe just maybe just a little tiny bit baggier than the aeryx pants, but the ronin stuff is way bigger around the waist line. I'm about a 36 waist and the ronin stuff is loose but the aeryx stuff is way tighter. I guess aeryx is supposed to be 38 but it sure doesn't seem like it.
Quality wise I'd give it to aeryx, their pants have way better material IMO, although both keep ya warm, the aeryx pants just feel better.