Been using Castelli for years. One psir so old it is getting a bit thin but hasnt torn. The Competizione are nice. Wide band at leg opening so no gripper sicone that chafes. Size up one from normal.
Regarding sizing, Iï¿½m 5-11 and 155 lbs, and tried both medium and large sizes. The medium was uncomfortably snug, so Iï¿½m using a large, which is very comfortable, though maybe slightly large for me. But Iï¿½m a casual rider and I donï¿½t like super tight shorts.