Switched from MX500 to G5r a few years ago, so i'm using this design since i abandoned my Trackball(first Logi Marble, still around) in '02. Tried the R.A.T. 7 a few months ago, but didn't like it.
I think it's better to use a certain mouse (form) for a long time rather that get the newest tech, because many (pro)gamers are far better with the Intelli rather than any other new tech-y mouse, so the tech is sufficient.
The general form of the MX(now Gx Series) is just it for me, exept holding the pinkie up gets a little tiring over time (4h+).
Said G5r is now slowly circling the drain, so i'm looking for a new mouse... think i'll get a Ikari, Sensei/Xai and a G400 and start a shootout (literally) session. If none of these get the job done right, maybe i can pick up a G5r at ebay.