Summary: I'm still trying to figure out what the DPI button on top of the mouse does. Just as a rough test, it seems to toggle sensitivity or increase / decrease dots per inch between two settings. Some complaints were pointed to battery life. I expect I'll end up buying rechargeable batteries, but this will bug me if it's a big difference. Just with use through the morning at work, I'm pretty happy with it.
Pros: - Decent weight - Super inexpensive - Mouse Wheel scrolls well (i.e. not fluid -- individual notches felt) - USB sensor deposits inside with the batteries - Tactile feel on buttons and side
Cons: - Battery cover a little annoying to get into - Batteries needed to be forced into their spot - "Gills" on the side of the mouse will probably collect hand oils and dust and be annoying to clean
Summary: Same experience like another user, it quit working once I replaced the batteries for the first time. It was not that cheap either. GEARHEAD will be banned for ever out of my shopping brand. Very disappointed.
Summary: Plug it in, it works. Being 2.4 GHz, it has great, very long range. Mouse shuts off automatically after a time of non use to save the battery. Any button press wakes it up. The circle (labelled DPI)at the back is another button that wakes it up too. Love the NANO receiver because it's small enough to leave plugged into a laptop without worrying it'll get snagged on something. The receiver can be stored within the slot in the battery compartment when required.
Summary: Pros: Easy to set up, just plug and play. Comfortable to hold for a nano mouse (even for big hands). Ribbed rubber grips on sides. Wheel is quiet and smooth while scrolling. Small dongle barely noticeable on side of laptop. Cons: No on off switch. Short life. UPDATE: After one month of light use, the mouse began acting erratically, the scroll wheel stopped responding and I found the batteries inside had corroded (don't know if it was due to Duracell batteries or mouse...