When you consider that a wireless mouse is a trade-off between convenience and absolute performance, the G602 seems like the best option available today in my opinion.
The long battery life, the use of AA batteries rather than a rechargeable li-ion battery, and a hardware switch on the top of the mouse to change between Performance (250/500Hz) and Endurance (125Hz) modes are all great convenience features.
I hate having to charge a mouse, so the option to have a pair of Eneloops charged and waiting is much better than the inconvenience of finding a micro USB cable and connecting it when the battery dies, or having to charge the mouse every night.
Tracking has been mostly fine for me at 750 CPI rather than 250/500, though you can still make it skip with fast movements.
Typically as CPI increases, movement speed decreases though, so it depends on what you normally use for gaming.
I do wish that Logitech had managed to adapt their Darkfield optical sensor to work in a gaming mouse though - since this is a wireless mouse it is not always being used on a desk or a mouse pad, and has a tendency to jitter on bad surfaces while the Darkfield sensor did not.
All of the buttons on the mouse are very well designed and thought-out in my opinion.
The CPI buttons are in such a position that you will never accidentally hit them in a game (I would not recommend remapping them to game functions) but the ease of access and the indicator on the side means that I can quickly drop the rate to 250/500 CPI on the desktop when someone else wants to use the PC. Without acceleration, even 750 CPI is "too fast" for people that are used to trackpads and touchscreens.
And I was surprised to find that having six side buttons is both useful, and that they are so well designed that I have not once made the mistake of pressing the wrong button.
In games, I use buttons 4/5 mapped to the same functions as my other mice which only have a back/forwards button on the side, and I have the rest mapped to Windows functions..
The 7/8 buttons above back/forward are zoom in/out (WIN+ and WIN-) and 6/9 launch the task manager/start screen - yes, I can really map them to the task manager/start screen without interfering with games.
The 500Hz polling and wireless operation are noticeable though. Especially when I switch from using the G602 to one of my DeathAdders, I immediately notice how much more responsive the wired mice are.
It's not that the G602 is bad - it's probably the best wireless mouse that I have used, but it is still obvious to me that it's a wireless mouse.
It is far better than any Bluetooth mouse that I have used though - they typically poll at 125Hz and have huge amounts of latency.
That does not mean that you couldn't make a good Bluetooth mouse though - strangely enough the trackpad on my DualShock 4 is polling at much higher rates than 125Hz.
However all the actual Bluetooth mice that I have used, including so-called Bluetooth "gaming" mice, have polled at 125Hz and had awful cursor movement.
Using a dongle (which can be stored in the battery compartment) for the wireless rather than Bluetooth has its pros and cons.
The downside is that you have just taken up a USB port on a notebook which may only have two ports available when you use this mouse.
The upside is that it makes this a very "portable" mouse, since you don't have to worry about pairing it to the system or downloading drivers.
The fact that it it can run off a single AA battery and has hardware switches for polling rate and CPI really helps with that too. It's great when I have to use an older Mac, since OSX used to hate anything higher than 125Hz polling, and I found that I had to use twice the CPI in OSX as Windows for equivalent mouse movement.