I currently use the Corsair M65 and I love it's buttons. Here is a quick comparison of the two:
Razer Deathradder: Adjustable thumb pads, gold plated connector (has been proven not to help performance)
Corsair M65: 2 DPI (How fast mouse moves) buttons, 3 DPI levels, sniper button (slows mouse down for precision movements for using sniper rifles), 3 adjustable weights (on bottom so you can change how the mouse responds/feels), full aluminum body (yes, it's much heavier than a plastic mouse but you get used to it and is more sturdy).
I am honestly sorry if I look biased to the Corsair M65. I removed all of their similarities and this is what I have come up with.