The thread is a little old but, it's still only second on this forum so I'll throw a post in here.
I too, hold the mouse with my fingertips which makes my palm hover over the mouse itself, and I found the R.A.T. mice (actually bought the old R.A.T. 5 and the newest R.A.T. model) difficult to work with because of this. These mice have a weight system that is able to be set up by the user as per their preference. The only problem I found with that is the chassis itself is so light, that when you load enough weights on the back of this mouse, I found myself constantly doing "wheelies" with it in situations with a lot of action. Pulling the mouse up far enough would make the lazer lose its position and cause the pointer on screen to stop moving for a split second until it came down close enough to the surface to pick back up. It is a cool mouse because it's fun to take it apart and reconfigure it to your liking, but because I normally hold my thumb on the mouse with a little pressure to help me move it around, I found the side buttons of the R.A.T. family to be difficult to work with.
I'm surprised that there wasn't a recommendation for the Logitech G700. I moved from a Razer Lachesis to this G700 and I haven't regretted it once. The G700 has an unlockable mouse wheel which I find myself using constantly to scroll through long web pages (usually viewed on a vertical oriented monitor) or when I'm trying to get down to line 2000 in some code quickly. Unlock, spin, and profit.
This mouse is also the only mouse that I know of (not claiming to have used all mice) that has left and right tilt buttons on the mouse wheel. By default the left/right tilt will scroll web pages and the like left and right but, seeing as every button on this mouse can be re-defined (unlike the R.A.T. mice I tried), you can use these buttons in games as well (WoW obviously doesn't interpret left/right tilt as anything in game until you remap it to a keystroke of some sort).
The Logitech software also lets you use different profiles per window/exe. So, for example, I can have the software remap the left/right tilt buttons to something else when the WoW window is in focus so that I can use them in game; however, if I tab out to a web page they are automatically back to being left and right scroll without me having to do anything.
It's a very handy mouse and I have recommended it to many, many people. I urge anyone who is in the market for a new mouse to give this one a try.
http://www.logitech.com/en-us/mice-p...ing-mouse-g700
I would suggest looking on other sites for deals on the mouse as you can usually find them.