Recently, I've been playing with the "lift off" function turned off. With this off the aimon feels much more responsive and I experience significantly less lag and acceleration. I have found that playing like this isn't without it's faults though. The lift off distance for the aimon seems really bad; which I can only guess is why they implemented a lift off function in the first place. After some searching around on the internet I found a simple solution - putting tape over half the sensor to decrease the amount of light that illuminates against the surface you're playing on. After doing this I went from a lift off distance of what felt like at least 1cm to maybe 1mm (about the thickness of a dvd). So now I am able to play with a more accurate, responsive mouse while successfully retaining a decent lift off distance.
Go here to read more about the "tape trick" and how it works to decrease lift off distance.