Honestly, I have a G7 and have used the G5 a ton of times and it still doesnt trump my good old MX518

The G500 is great for the metal hyper scroll wheel, but the last mouse i used with the sensor at the top was a logitech MX700 and i HATED it.
What id recommend is find somewhere where you can try the thing out first, because it will def feel different to other mice.