And which sensor has 5700 DPi?
Well, thats that "issue" cause there isnt one.
Avago 9500, widely used and its like 99% probability one in Sensei (aswell as in Xai), has native 5040 DPi (or CPi as SteelSeries likes it). Phillips Twin-eye has 5600 DPi. Mostly used in Razer mices and some special things, like R.A.T. mouse.
So most likely, this mouse has as Xai, just native around 5000 DPi.. everything else is just interpolation. Unless one believes SteelSeries to tell the truth.
Its similar to truth from Logitech and their G9x or G500 to have 5700 DPi from 5040 DPi sensor..