Mousepads impossible - High weight - Accurate

The M510 is difficult. The first time my wrist is asleep at 9 hours of continuous use several times. Actually, we are talking about a few grams, but which become noticeable. And no .. It is my 6th mouse since 1996, so I know what is normal :) The solution was that I had removed one of the two batteries, then it was solved. BUT:
The mouse works only on very specific substrates .. The laser really are a joke and part of the worst I have ever seen. Shame on you Logitech!

On rough Speedpad? Result: mouse shrugs
On Fabric Gaming Pad (Speedlink): mouse only shrugs
On cheap pad for 3: Mouse goes too slow

It takes a very, very special fabric so this mouse runs. I had the mouse 510 times in the bed tested while surfing because you running properly. So for me, a big nuisance, that would be flunked as Quallität tester with me.
Oh, workmanship is very good. Size is normal .. Who a Dual Optical or MX510 fits, which is also this mouse fit in the hand.