The driver:
I have never had any luck with mouse drivers. I usually just use windows default drivers with a mouse registry fix installed. After a bit of playing with the mouse, I wanted a bit more control over the dpi setting. So, I installed the drivers.
The first screen is a typical one, showing the buttons and assigning them to different keys or just explaining what the default settings are.


The pointer screen is the normal fare with mouse speed controls and pointer acceleration settings.


The game screen gives the option of having different settings for playing games and for general use. This is nice because keys can be assigned to browse the web or can be used as default keys in a game. The speed and acceleration setting is one of the best features. You can have the mouse driver take over all control of mouse acceleration. I tried this on a PC without the mouse fix and it killed all mouse acceleration. This could come in handy for those LANs that do not give you the option of installing or removing the mouse fix.


The advanced game settings are where we get to change the dpi settings for the optic sensor. By default, the mouse starts off at the middle setting. The settings can be changed to any extreme or just a tad to give you a bit of a speed difference when it is needed.


Play testing:
Having already stated my dislike for mouse drivers, I first started playing without them installed. The dpi sensor is on the mouse, so settings can still be changed to 400, 800 and 1600 dpi. My old mouse, the MX 510, uses 800 dpi and the in-game feeling is the same. Changing from 800 to 1600 is comparable to using a jet engine to turn around. In other words, it is a bit too fast for my liking. Dropping down to 400 has that “playing in maple syrup” feel, meaning it is way too sluggish for playing.

After installing the drivers, I changed the default dpi to be a bit more reasonable I set the low to 600, the middle to 800, and the high to 1000. I just do not see the need to change mousespeeds to such extremes as the default (which as I stated was 400, 800, and 1600) and I did not want it to feel to differnt from my old 800 dpi mouse. Then it hit me: Why the hell do I need to change my sensitivity on the fly? I started to play some Counter-Strike and looked for any excuse to change mouse speed at will. The first thing I came up with was moving out of spawn. That slow mouse speed moving into position has always nagged me. It is no problem now though, as I just raise my dpi and move into my spot. A fast mouse speed is not needed as a Counter-Terrorist when looking at the long A double doors on dust2. I just slow it down to the lowest setting. Out come the flashes and grenades, and I am blind, but I just speed up the mouse, turn, and run like hell. Then I slow it back down again and pick them off as they try to jump into the pit. Hey, this is kind of fun. It has also given me something new to change every time I play poorly. Forget hitting console; I will just click these buttons.

In every game that I played the buttons worked as they should. Logitech has a bad reputation regarding mouse buttons four and five not working unless they are assigned to a keyboard key. However, it seems that they have solved that bug. The negative acceleration that plagued earlier drivers seemed to be gone as well. The MX500 tracked just as well in even the fastest games.

Conclusion:
After a month of playing with the mouse, I have upped my default dpi to 1400 and will not go back to 800. Besides some long-ranged fighting in UT2K4 and watching doorways in Counter-Strike, I have not had much need to change the dpi settings. This is just not something I see competitive players changing too much since consistency is the key to success, not random mouse speeds. Overall, the mouse performs well and is what I would expect from Logitech. If you are in the market for a new mouse, this is the one for you. If you are happy with your current mouse, however, it is not worth the upgrade.