When comparing Logitech G602 vs Logitech M570, the Slant community recommends Logitech M570 for most people. In the question“What is the best mouse for programmers?” Logitech M570 is ranked 11th while Logitech G602 is ranked 19th. The most important reason people chose Logitech M570 is:
Using a stationary mouse will keep wrist and arm movement down. The trackball being operated by the thumb makes for great comfort (do not recommend finger based track balls). A trackball doesn't require a large flat surface, though next to the keyboard still tends to be most comfortable.
Specs
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Pros

Pro Comfortable for palm grip with easy to hit buttons
Great for palm grip along with a the fantastic logitech software for key mapping and profiles.

Pro Great battery life
Good for users that want a wireless mouse without any loss of functionality or need to change the batteries every week

Pro Good optical sensor
Only up to 2500 DPI but it's a great sensor for those that don't need very high DPI.
Pro Can run on single battery for lighter weight
Users can opt to run the device on a single battery to cut down on the weight but this will have an impact on battery life.
Pro Trackball
Using a stationary mouse will keep wrist and arm movement down. The trackball being operated by the thumb makes for great comfort (do not recommend finger based track balls).
A trackball doesn't require a large flat surface, though next to the keyboard still tends to be most comfortable.
Pro Wireless
With 18 months of wireless power, it can be used in a variety of manners not handicapped by a wire.
Cons


Con Somewhat heavy
Being that this is a wireless mouse there is the battery weight to contend with. Batteries in the weight of the device is 152 grams, which isn't all that bad considering but still not for users that like a lighter mouse.
The mouse can also be used with a single battery, which is useful for not only reducing weight but also for balancing the mouse. With two batteries the mouse can be a bit slipper on the right side when picking it up as the pinkie and ring fingers don't have as much to grip - but balancing the weight over towards the thumb allows the mice to be more easily picked up as the side buttons allow for a decent place to grip.
Con No wired option
The Logitech G602 does not offer a wired USB option, only wireless.

Con Macro Key Defect
Side buttons are known to register multiple keystrokes occasionally when pressed only once. With bindings such as Ctrl+F4, this naturally has destructive results.

Con Middle mouse button wore out after a year of heavy use
And with no way to open it it's near impossible to fix.
Con Low build quality
The shell is very cheap, thin plastic and the button sensors are either far too easy to trigger (left/right click) or ridiculously hard (back/forward, middle button/wheel).
Con Really awkward with the left hand.
Doesn't really go both ways
