I've had a couple of Razer mice over the last few years, they're very comfortable - at least their simpler ones like the Death Adder. I have had problems with the switches across two mice from them. May just be bad luck on my part though and I do get a great deal of use out of the things.
If that's not a concern to you, I'd recommend the Death Adder. It's simple, and at least for my oversized mits quite comfortable.
The Imperator has a frustrating lift-off distance, IME - so if you were choosing between the two I'd avoid that one.