Let me tell you a cool story. A guy called gr1m bought a 1800dpi first generation Deathadder a couple of years back. One of the side buttons caved in and it got filthy to a point of being impossible to clean, so a month ago gr1m decided to upgrade to the next "top dog" in gaming mice, the Logitech G500.
Gr1m knew that the laser sensor on the G500 was purported to be just as good as optical sensors, which up until the G500 were hands down superior to any other laser sensor (for example, the Deathadder's 1800dpi 3G sensor is quantifiably the highest performing sensor to date).
A month later, after jiggly cursors, erratic scrolling and lots of discomfort (probably because Logitech mice are big and heavy as opposed to the Deathadder which is light and small), gr1m pulled out his old, battered Deathadder, put the G500 in his closet and now he can snipe in TF2 again. He is one with his mouse once more.
Long story short, try to get your hands on an old Deathadder for the best tracking experience of your life. You might not like it's other aspects though, it was a ***** to get used to when I first bought it and Razer has pretty bad support and flimsy build quality.
*edit
On a side note, I really don't know where you can get an old 3G Deathadder these days (there's only the updated 3500dpi model floating around and it's laser, so it's not worth the trouble). I e-mailed Razer to see how I could get my hands on a brand new 1800dpi Deathadder. I'll post when I get a response, if you're interested.
Steelseries Ikari or Xai.
To add to this, the Xai apparently has the same optical-matching laser sensor of the G500, except without the problems that plague the G500 model. Worth a shot if you have the money. I might just buy a Xai myself.
