Counterbalance makes your recoil up and down only. Rodeo makes your shots group together more closely. Both are good, but very few actually know what Rodeo does and therefore most claim it does nothing. Most will tell you to dismantle anything with Rodeo on it; I'd strongly recommend you ignore that awful advice and try it out yourself. You can test both on a patrol by shooting walls or whatever. Counterbalance will make recoil completely vertical, whereas Rodeo will not change the direction of recoil but will make shots group together more tightly (very nice for followup headshots, especially if your first shot is a critical hit).