If youre talking about Razer Mouse, Krait, Diamondback, Copperhead size are all about the same, but DeathAdder is kinda bulky.
Diamondback is nice to grip on. Copperhead is nice at the Razer logo light. Right now Copperhead is more pricey than DeathAdder. But latest mouse Razer produce is DeathAdder. They are going to produce another Editors Edition mouse, BoomSlang. Priced at $99 USD. Not sure when it will be released.