Bests & Worsts Reviews from Amazon

I have about 5 of these. I have 5 because i have multiple computers BUT ALSO BECAUSE THESE DO NOT LAST. I LOVE it & how it works. I have NOT experienced some of the problems some other reviews talk about. I work a LOT using this (& the others) mice so I give it a good work out. One particular button on ALL OF THEM gives out. The inside spring gets loose (I guess). It will work but I have to press extra hard. Usually it will not hold for a copy good. I started to take the unit apart to find the spring to see if I could tighten it. The unit is not made to be taken apart of repaired. I phoned Logitech & they verified this. SO for me, it lasts 1-2 years & Then I Must buy another. Pretty sad for a major company like Logitech. Today I TRIED to communicate with Logitech to see if they had improved this model. Their "chat" sessions never opened (I waited 15 minutes). I tried to communicate by phone. They offered a phone number to call. That number referred me to a different number. That number said they are no long monitoring the number so please go to their website (where the chat doesn't work. Needless to say, I am less than impressed. I still like the layout & feel of this mouse WHILE IT IS STILL NEW. So, it is 5 stars until it breaks. Figure you can get 1-2 years depending on usage.Then it is almost worthless.Plan on buying it over & over if you like it as there is nothing else in the market like it.