Using this mouse for a few months, I got accustomed to. Indeed I separated from an old wireless mouse but not Bluetooth. I plunge into the bluetooth because I was tired of meeting the USB receiver with my mouse (USB port on the right side of the computer). At first contact this mouse using two LR6 appeared to me heavier than the old one, but this was soon forgotten for use. Accurate and reliable, it is recognized immediately in Vista, (not even need the dedicated software). I have not encountered any problems from running. I recommend.