I was going to say: local shop has team jerseys from Castelli. Although they are both race type, one is standard race cut, and the other is what the shop calls their "climber's" jersey (lower collar, tighter, slightly longer sleeves, finer, mesh-like fabric). Tried them both. Regular race jersey fits fine in Medium - properly trim, but can be zipped up without really noticeable stretching. Climber's jersey in Large, the fabric definitely has to stretch in order for it to be zipped up. Kinda makes sense. Although quite slim, among competitive cyclists, I'm pretty average size, but among climbers, I'm on the taller side (hence slightly larger).