Is is worth it to pay extra to get the copperhead over the diamondback?
The side buttons are better on the Copperhead, but it continues to track if you pick up the mouse. The Diamondback doesn't.
While the Razer mice have a very low profile, it's rather comfortable to use them once you get used to the different feel of them. The extra long mouse buttons took a little getting used to, but I love 'em now. I can click with a twitch of my finger... I don't have to curl my fingertips to rest on the buttons.