AFAIK the current Razer Deathadders still have the best sensors bar none.
This is my experience too. None of the laser mice have quite had the tracking abilities of the Deathadder's 3500dpi sensor.
Razer say their optical sensor does 60–120 inches per second and 15g of acceleration, which I totally believe.
Razer say their lasers do 200 inches per second and 50g of acceleration, which I can disprove with nothing more than a mild wrist-flick.
Logitech are less boastful of their lasers, claiming 165 inches per second and 30g, but again - it skips on fast movement no matter what surface I try it on.
My understanding of this is that lasers are TOO DAMN FUSSY; They may have superior stats on paper, but those stats relate to "optimal surface in laboratory conditions";
I can make most laser mice I have tried skip and screw up quite easily (even though I now use one for gaming). I say most because I tried a Taipan which uses two sensors (laser/infra-red optical) and that performs more or less as well as the old Deathadder.
I'd have bought another Deathadder if the build quality wasn't so shocking