In my experience the first thing that always fails is the scrollwheel. My g500s is going strong after about 10 years because it uses an optical scrollwheel instead of a potentiometer. I think this is a very important difference BUT IT IS NOT ADVERTISED OR DISPLAYED ANYWHERE WHEN YOU WANT TO BUY A MOUSE. Ridicolous. Soooo annoying. I hate marketing.
Have you heard? The release candidate of 1.0 dropped just a few days ago. It looks very interesting.