When I received my free Logitech G9 from Logitech as the replacement for a broken G7 cordless mouse, I was naturally eager to see how it compared. I had loved the shape and feel of the G7, and was somewhat wary of the G9's different design.
Thankfully, as I began to acquaint myself with my new mouse, my fears were quickly laid to rest -- for the most part. The mouse's default shape feels very natural in my hand, and though the mouse features a swappable outer shell to support different shapes, I felt no need to change it out (though for those with unusually small or large hands, this presents an attractive option).There are more than enough buttons for my needs, and I doubt even a real power user or gamer could want more than seven fully assignable functions besides left/right click and scroll.
My one great disappointment with the G9 was the changed button placement of the sensitivity up/down buttons. The G5/G7 design featured the two sensitivity buttons right below the scroll wheel, one above the other.This made those buttons, ordinarily rather useless, into a natural choice for the "Cruise Up/Down" function, which is a fantastic way to travel up and down a web page or document quickly. Sadly, not only does the G9 have no such convenient buttons (I have resorted to using scroll wheel left and right), the maximum speed of the Cruise function in the SetPoint software is inexplicably reduced from that of the earlier mice, making the function much less useful.
Indeed, the SetPoint software is the only true weak point of the mouse. Thankfully, Logitech has fixed the bloatedness issues with the program (when I first got the mouse, the installer weighed in at over 80 megabytes), and now it's quite competent. In fact, the amount of configurability it offers is astounding -- any button can be mapped to just about any function, including keystrokes, and the mappings can change based on what program is active.
However, some annoyances remain -- sometimes upon starting the computer, SetPoint will fail to recognize the mouse, making any specially assigned buttons like my Cruise settings do nothing. Upon bringing up the SetPoint window and clicking on the mouse in the device list, the software says the mouse is not currently associated with the computer, and asks if you would like to associate it, thus wiping all profiles assigned to the mouse. To get it to recognize that the mouse does in fact belong to the computer, one must quit SetPoint and reopen it, then click on the device. I've had to keep a shortcut to SetPoint in my Quick Launch bar just for these occasions.
Aside from this minor software issue and my personal annoyance with the moved buttons, however, this is a great mouse. It's precise, configurable, comfortable, and reliable -- everything you would expect from such a high-end mouse. In the end, though, there are only so many "features" anyone could possibly need from a mouse. The advantages of the expensive G9 over the more modestly priced G5 (whose design I still prefer) are dubious at best, and overall don't justify the purchase. If you're shelling out the cash for a new mouse, I recommend the G5 -- but if you happen to be given a G9, you certainly have no reason to complain.