I love my BT mighty mouse. Feels good in my hand, love the little "nipple" -- works really quick and smoothly. Have seen posts that indicate they get dirty quickly and need frequent cleaning, but in 3 months of use, I've not had any problems. Biggest "problem" is that when I take the MB from my desk into the living room (two walls, about 20 feet), the MB still recoginzes the MM. I always forget this, and have to go back and get it or go back and turn it off to use the trackpad! Not much of a "problem", I'd say -- great range! 😉