From someone with an MX518, get a G500. Same mouse but better, what cannot be said for the MX518 -> G5 jump.
It just doesn't get any better as far as the number of buttons go, and the DPI/response is equal to everything else.
V1 is amazing. How they could cut the number of macro keys to a third of the V1s and call it an "upgrade" I don't understand.
The screen is much nicer as well, being able to adjust it and whatnot.
How exactly can one claim scoped kar over Springfield? It's not that the kar is bad, but the Springfield's scope is a work of art. Otherwise aren't they identical?