Almost two years ago I bought the G9 gaming mouse from Logitech (note: This is NOT the G9x mouse). This mouse cost AUD$179 at the time.
I have to say I love it but for some small (crippling really) issues.
First, the bad 1) The braided cord: Logitech tout the cord as an asset. In reality it seems to be the biggest fault. All G9's I have seen get broken wires inside the cord. I seems the braid holds twists in the cord and cause the inside wires (which are really thin) to eventually break. I have had to slice and dice mine to graft on another USB connector.
2) The buttons: For a gaming mouse you would expect the buttons to be the toughest feature. Not so boys and girls.... I have to now push pretty hard to get my first button to click.
Now, the good, 3) Change resolutions on the fly: This is awesome. If you're not a gamer then this doesn't mean much. If you are then the ability to go from slow mouse movements as a sniper to huge speeds when you jump in a plane is so invaluable I am almost happy to overlook the bad issues.
4) The lights change: Now that sounds lame but I love the pretty colors. The mouse allows you to store many profiles "in" the mouse once you have configured them using the software. I have three major profiles set. "Red" for gaming, "Blue" for work and "Orange" for web surfing. The "Red" profile has all the button set as blank so I can configure them in-game and my resolutions set at even intervals. The "Blue" and "Orange" profiles have most of the buttons mapped to different keystrokes so that I can do lots of stuff from the mouse.
5) The scroll wheel: I love this wheel. The wheel has two modes; a geared mode where it will only scroll one 'click' at a time and a free mode that will spin up to 7000 revolutions. I love the free mode. I can go from the bottom to the top of a Excel, Word, PDF or any type of long document with one spin.
Would I buy another?
No. not for $179 again. Will I continue to hack and solder this one until it looks like it was made in my garage? You bet.
Should you buy one? ONLY A BRAND NEW ONE WITH WARRANTY!!!