You are all familiar with razers 3g and 3.5G infrared mice, all of them are well reputed for their 0 acceleration and their ability to track at insanely high speeds, I would say one of the best sensors out there for FPS gaming, but due to the sensor having a 1.0x mag factor lens instead of the 0.5x lens alot of companies are using now days the sensor had a bit of jitter (the 3g did not have this and the deathadder v2 had this fixed over firmware update) when lifting the mouse up.

Now most people thought that the jitter in the 3.5G was a hardware problem but it was essentially removed in the deathadder v2 with a firmware update, unfortunately razer was not kind enough to support the abyssus with firmware update capability, there is a workaround for that and this workaround also reduces the LOD (lift off distance) of the mouse which hampered its overall excellent performance.

The way to do this is to partially cover the sensor with a white piece of paper, now the thicker the why paper the lower the lod also if more of the sensor is covered the LOD is reduced, but increasing the thickness or the amount of the sensor area cover also hampers the sensors tracking on the surface so dont cover more than 40% from the bottom rectangular side of the sensor, the thickness as well shouldnot be too much, but then again do experement with this mod and see which result suits you best. Ill upload pictures and more detailed walkthrough for this later ^^