I couldn't have said it better myself. The article lists every reason that I take part in Betas and the appropriate approach to feedback.

I was amused by the "if it doesn't install, the Beta evaluation ends though". In my experience about 30% of Betas don't install properly on all platforms - probably 40% on MS products! I always sigh, and then try and figure out ...just...exactly...why...the blasted thing will not install before I get to start! 🙂