Razer abyssus or deathadder?

Both of these products have almost the exact same specs, but the abyssus is $10 cheaper than the deathadder. I feel like the only extra components the deathadder offers is the 2 extra side buttons, which i'm not sure would help alot. I play alot of fps's, and I don't really use the side buttons at all. Should I buy the abyssus, or deathadder?