I 5'11-6' and 155 lbs. I ride a 56cm bike but I recently found a 54 that is a super sweet deal. I do road riding and race. Is it a big mistake to go for the 54? I can get a longer stem and of course seat height is adjustable. My main concern is if I am giving away efficiency or handling performance since I do race. Comfrot is not a big deal, it's a road race bike and I have a flexible body so I can adjust well.