Compact mouse with a penchant for "Zappel-Philipp-existence"

I use this mouse now for about a year and unlike other "mice" in this affordable price range has me the USB mouse of Hama not let down.
The connection was fast and easy, provided small USB plug into the PC, mouse with batteries and away you go.

+ Compact mouse that fits comfortably in your hand
+ Uncomplicated connection
+ Pressure points of the keys well, as reaction of scrollwheel
+/- Batteries can be difficult to take out of the housing (especially the latter, which is simply sunk too deep in the body)
- The really disturbing point: mouse is very slow, if it is on smoother surfaces such as desk top. They often do not respond here
- Even if I do not touch the mouse, the mouse pointer sometimes wobbles across the screen

Overall, I'm up on the points mentioned quite pleased with the mouse. It is not outstanding, but I do not expect for the reasonable price also.
From me there is 3.5 stars for the little mouse.