Got the Logitech G PRO Wireless to try out.
Thoughts so far after a few days, good shape and size (feels a little small but i'm used to the rival 310 shape right now). The feet seem very similar to the Steel Series Rival 600, they are very loud and have little initial friction, decent glide. For comparison the Rival 310 has a much smoother, almost silent glide, but more initial friction. Overall I feel the feet on this are better.
In my experience, as with mouse pads.... The more consistent you can make 'glide' feel, the better... If you need to lower the overall 'slickness' of the glide to obtain less starting friction I'm all for it. It's like i explained with mouse pads, i feel manufactures could really spend time to look in to improving them, the slickest, smoothest surface does not necessarily give the smoothest, most consistent glide.
The buttons, scroll wheel and clicks, overall quality as usual from Logitech, feel great. This is also the lightest mouse i own, coupled with wireless... feels amazing.
Overall i'm really liking this mouse, i don't see any real negatives at this point, Great job Logitech!
PS: The side buttons are in a better location for me as well, my thumb sits right in between the buttons how i hold this mouse. The steel series 310 felt like the buttons are slightly too far forward for where i grip it (Steel series 600 was actually perfect).
Also as an update on the Rival 600, i had to return it as the Lift of distance was changing randomly, to the point i would lose tracking during a game. Also the shape was not perfect, i did not have a great solid hold with the mouse, mainly because of the right side and the lack of geometry.