I have this mouse. I bought the MS 6000 laser notebook mouse instead. Still have this Logitech one. I love it in every way except one -- the stupid touch-sensitive mouse wheel replacement. It's impossible to use this mouse for any length of time without accidentally touching it, causing whatever you're working on to spaz out with rapid scrolling. Even if you deactivate the "wheel" in the software, it still audibly clicks like crazy any time you accidentally touch it - this can't be turned off. And who wants a high-end mouse without any scroll feature?
I love, love, love this mouse, but this one problem means I'm getting rid of it. Anyone want to buy it after that review?
BTW, the two AAA's are nicer than using a AA, IMO. 2 AAA's are smaller than one AA and allow the mouse to be flatter. Either way, I use NiMH, so I don't care about what the relative costs might be.
If this thing had a traditional mouse wheel, or even a decent raised ridge to prevent accidentally touching the side of the mouse slider "wheel", I'd keep this over the MS Mouse in a second.
One nice feature of the Logitech software is that I can have separate resolutions for my mouse and my touchpad -- i.e., my touchpad continues to work as normal. With the MS software, they both share the same mouse res. That means that my laser mouse cursor screams across the screen uncontrollably fast, or else my touchpad requires several rapid swipes to push the cursor even half-way across the screen (which is how I have it set). Neither mouse is perfect, but the Logitech's single, solitary flaw is fatal (for me).
One workaround is to leave the side-scrolling feature active. Then at least if you brush against the mouse slider "wheel", you don't get lost vertically in your document or program window. If there is no horizontal slider at the bottom of your window, you might not get any negative effects other than the "click-click-click."