What about the Steelseries Xai? I use that at home for FPS games when I'm feeling competitive. It's flawless.
Agreed 100% +1 for Naga - I recommend everyone and anyone to use it. Only reason I don't use the Xai full-time is because it lacks a tenkey.
The Xai has positive acceleration due to its Avago A9500's sensor, so it's not considered to have flawless tracking.
may i ask what tracking issues your talking about ive never had any trouble with it...
If its that minute bs that you have to test to find, i dont consider that a problem 
http://forums.logitech.com/t5/G-series-Gaming-Mice/G600-Mouse-Movement-issues/td-p/863548
http://forums.logitech.com/t5/G-series-Gaming-Mice/G600-Mouse-Pointer-Delay/td-p/904278
And the Avago A9800's positive acceleration.
All made worse by the G600's non-flashable firmware.
Personally, I "found" all of these without any testing. If you don't game or don't take gaming performance seriously at all, I guess these won't be an issue, but then one has to wonder why you'd even purchase a >$60 gaming mouse.
Most laser sensors have either positive or negative acceleration with the PTE being the only exception that I know of, although that has other problems. I've found that, at least for me, I can't use the G600 comfortably at the levels where these issues would actually bother me.
High sensitivity players probably won't notice this at all and low sensitivity players should be using optical anyways due to the higher tracking speeds.
The fact that the G600 doesn't perform optimally in FPS, which is about the only genre where the laser sensor issues are really worth mentioning imo, is rather moot as the mouse is made for MMO use where you can perform just as well with a laptop trackpad.
However, if we take a look at mice like the G9x, G500 and, well, pretty much every high-end gaming mouse, then your points are far more valid. It's sad that the dpi hype means that mice with a great shape like the G9x are not as good as they could have been if not for the idiotic quest for higher numbers.
Edit:
Boy I'll woop dat ass in scoutzknives, or any other CSS map. WITH my Xai.
Nobody ever said acceleration was a bad thing, some people prefer it, the only reason I have an issue with hardware acceleration is that I don't want to be forced to use it. But that's the way it is, as far as I know the acceleration issues are a result of the limitations of the laser technology, although I seem to remember at least one large manufacturer pushing for perfect, or at least better, laser sensors.
