I've been switching between my Abysuss (3.5G) and Kinzuadder (3G) recently and I've noticed that the Kinzuadder with the old deathadder 3G sensor is tracking much more solidly than the abysuss. It feels more solid and never misses a beat even with the fastest of movements - which is to be expected. The abysuss just feels less solid and tends to error sometimes with fast movements. It miss tracks and leaves me looking vertically.
I actually prefer to use the abysuss because it's slightly lighter, has less friction and a better positioned sensor so I'm not too pleased about it letting me down. I use a alpha goliathus which is nice and clean. Is this something to expect of the abysuss after a certain period of use? I've only had it about 2 years, probably just less.
The kinzuadder tracks perfectly, I just find the sensors too far back for me and the mouse feels a little small.