Summary: I believe this mouse represents the pinacle of design/function that logitech has produced in the past 7 years. It has made it through first person shooters, mmos, rts, and years of design and cad work. The design of the mouse is perfect for my hand, though a bigger person might take issue with this mouse slight smaller than standard frame. The curves are in the right place so my thumb and pointer fall on the corresponding buttons.
Excerpt: The best mouse I have ever used. The shape fits perfectly on my hands (I have fit medium size gloves). I have used many laser/gaming mouse in the past and nothing beats this. There is a huge improvment from the g5 v1 to the v2. The material of the mouse is very different. The g5 v2 has a nice feel to it because it hand will never get sticky or sweaty. The cord is very long.
Summary: I've tried quite a few including the G500, which I still own and use at work, the Cyborg Rat 7 (gimmicks nothing more), the Razer Naga (some heft please), the G700 (ehh) and I've always come back to my tried and true G5. I use all buttons including the side-scroll buttons and, combined with the weight and perfect ergos, this mouse has just worked perfect from jump start.
Summary: This is quite possibly the best mouse I've ever had. I used to use it at school a lot and really liked it, as they had these in one of the computer labs there. After my old mouse died on me, I decided to give this one a try since I had already used it before and found it to be much better.
Summary: Great mouse! I had the previous version and loved it. This one adds a button and feels even better to the touch. I now own three for all my computers. I'm not a gamer, but find the precision and on-the-fly sensitivity adjustment helpful for photo work and other exacting tasks. And, it just feels GREAT in the hand. Significantly improves the computing experience.
Summary: In comparison to the G9: I was using a Logitech MX510 prior to this mouse. The MX510 was over 3 years old and started having issues with the sensor and since I liked that style this seemed like a natural match. I ordered the G5 alongside the G9 to compare and contrast the top contenders. Overall the only real difference in usage are the scroll wheel on the G9 and the types of grips offered.