Not sure wheather these sensor differences 16k DPI and 18k DPI really make that much of a difference?
For most of people it wouldn't make any difference if it was 2000 or 18000 dpi sensor, as long as dpi is the only factor that differ.
Since all pmw3360-3391 variants are pretty much the same hardware-wise it's literally nothing but a gimmick.
Dude.. no why, just get a Logitech if you want wireless. Logitech wireless is way better than competition and the only viable one, that's why the whole wireless craze. It's not that suddenly wireless mice now are good. Only Logitech and they still mess up with stuff like wireless headphones (lol yeah wireless craze). 3366 has less smoothing than 3389, and you don't use 10k+ cpi for gaming.
Plus that corsair thing looks heavy and bulky. Look for light weight not high cpi