Positives:
+ Handling is super
+ Good response times for a wireless mouse
+ Range is also very good
Negatives:
Driver crash, bringing the complete PC to a halt
Battery (Ansmann Photo batteries, Eneloop) hold approximately 4 hours !!!
-The Gum dissolve in a sticky mass, not an isolated case, since I after 7 months have the problem again even when the replacement mouse.
I would anyway never buy again.