Cons:Terrible tracking. Skipped/floated everywhere. Hard to hit links/buttons on screen.
Size too small.
The Bottom Line: Horrible. Think the sensor is not up to snuff. Use on high res monitor (24") may have exacerbated the issue. Caveat emptor-especially if used to higher DPI sensor mice.
Bought this mouse when my much loved Logitech G7 wireless mouse finally gave up the ghost. I had thought (and hoped) this mouse would have everything I needed - back/forward scroll buttons on the left side, and optical/laser sensor for steady movement.
After getting the device home, I plugged it in and to much consternation found it wasn't going to be as simple as plug-n-play. No, instead I had to fool around with dowloading and installing Logitech's Setpoint software, and then when that didn't work, I had to download their Unifying software. This second program worked to get my M705 up and running on Win 7 x64.
Unfortunately, the mouse itself didn't pass muster. First, and most eggregiously, the mouse movement was terrible - I suspect due to the sensor - and using it on my bare oak desktop (as I've been doing for years with my previous G7 model), it was simply terrible. It couldn't keep a steady straight line across my desktop, it would undulate across the screen with variances of half an inch or more off track. It skipped and was atrocious when attempting to move onto a small 'button' on websites or games...invariably missing the mark and making me sit there and circle until I could click my link. Terrible! To determine if it was just in my head, I quickly created a 'jig' (a la woodworking) with a book and ran the mouse along the spine to see if the mouse floated on screen when held to a steady straight line. As suspected, the mouse moved across the screen as if it were riding a tiny horizontal roller coaster...undulating up and down by as much as half an inch. Logitech you should be ashamed. The problem persisted when I tried to use the telephone book as a mouse pad. Still not tracking properly!
Another bother I noticed - when surfing, if the website I was on (i.e. ESPN or Youtube) had a video playing, the 'back' button on the side did not work. Strange - I've never seen that shortcoming in a mouse before. When surfing through folders or webpages without video playing, the side button worked fine.
Finally, I thought the shape and size of the mouse were notable. The shape was nice, but the size was about an inch too short for my medium sized hands. The back/forward buttons were ideally located for my thumb.