It depends on what your needs are. I recently bought a R.A.T 7 and it's on a completely different level comfort-wise from any other mouse I've used. The Rats are the only mouse types that can claim to be ergonomic since it's adjustable. There is no one-size-fits all. The only drawback for some (I've heard), apart from the price is that it's a heavy mouse, even with all the weights removed, but that's only because it's built properly. For me it's just perfect with 2 extra weights, and that sniper button is a godsend.
I've never been a fan of the Roccat products because they seem to, like the Razers, feel a bit flimsy and "cheap", even though they are anything but cheap. They're also designed for a palm grip (the ones I've seen, Kone etc)
The Logitech might be a good choice if on the other hand, you don't use a palm grip at all. I used to love Logitech products, they're quite solidly built (although not as good as the R.A.T) and last a long time. If I hadn't discovered the awesomeness of the R.A.T, I would have gone for the G9x myself. It's fugly but it does a great job.