Overall the mouse is good.

I had read the reviews about the mouse being small, but was undeterred. The mouse is not small, its just downward sloping (back to front) and nearly flat on the front half. It could be confused for being too small, but it is just not shaped to fit a cupped hand.

I like the mouse, it has been capable of all things a mouse should be capable of. And it was relatively inexpensive for comparable mice. If I were doing it again, I would go for a more ergonomic mouse.

I'm a fairly hard-core gamer. I've used top-line Logitech gaming mice and always keep coming back to the good old MX-310. All the fancy buttons and resolution options are worthless if you don't use them. And forget that middle side-scrolling button if you're a gamer--it makes using the middle button for firing darn near useless, IMHO. This is a great fit, great response, and really, all the buttons you need at your fingertips. I'm ordering a couple extra just to keep on hand (I'm hard on my mice). I even use it at desk at work (tho there I do miss the side-srolling a little, but only a little).
If you want a really, really GOOD, inexpensive mouse (that Logitech doesn't itself sell anymore, boo on them), you gotta get this one!

As has now been documented elsewhere, this mouseware conflicts with other Mac extensions. Specifically, the iMac won't recognize my camera anymore.

This was an enormous frustration, and Logitech is distinctly unhelpful, between their website and their customer service.

You have to disable the mouseware in order to get the camera to show. That of course renders the mouse functions nearly unusable, down to only the basic point and left-click.

Be forewarned, fellow technology laggards!

This mouse WAS awesome! It worked excellent on my Win98se desktop Hewlett Packard Pavillion 6730. I now own a 32 bit Sony Vaio laptop Vista Home Premium and it works slow. I don't think it is compatible with Vista. I recommend that you email Logitech before buying this mouse for compatibility info. I now own the Logitech LX8. Cordless(batteries), heavier, larger, and the forward/back buttons can press too easily(less resistance on LX8), but once you get used to the LX8 it's ok, at least for me. The LX8 scrolls much, much better than the MX310 but that's a Vista issue, not a mouse issue, I think. If the MX310 mouse is compatible with your operating system I highly recommend.

My favorite mouse of all times (including Mickey). My first MX-310 was over two years ago and I am using it daily without problem since then on both Windows and on Linux (Ubuntu) via a KVM.

Subsequently ordered a second MX-310 last year, and now I plan to buy a third so all my workstations can have their own. I don't use the side buttons much (never tried to get used to the back and forward buttons) but I use the scroll wheel all the time when browsing on windows IE7 (doesn't seem to work with Firefox on Linux, probably a configuration error on my part). Can't think of much to improve except maybe move the side buttons closer to the front so I could push them easily without regripping. But I presume the hand movement is good exercise. No carpal tunnel yet (crossing fingers!)