The original Commodore ones have their problems, too, tank mouse and the 600/1200 mouse use the same low-quality switches for the buttons, I've had to replace more than a few of these.
The "pregnant" mouse, however, has higher quality "clicky" switches and is the best mouse Commodore made for the Amigas.
I have completely differen experiences. My tank Mouse from 1988 is still great despite the fact I used it ithe most, while the "pregnant" that came with my A3000 had to be fixed.
I also once bought a cheap Beetle-mouse. Maybe the "new" Amiga-mouse is like them: you had to open it and adjust the sensor to make it reliable. All that was required was a little bending to make the light beam parallel. After the fix the mouse was really usable for DPaint & stuff.
