We get hail here in colorado, and high winds. So far, of 20kw installed among myself and my family members, we have not had a single failure. (5 years for the oldest installation, 1 year for the most recent).
I had golf ball hail hit mine about 2 weeks ago. They are mounted at a variable angle, this time of year, it's usually 55 degrees. No damage, although they are covered under my homeowners policy without any extra riders.
They certainly can be broken, but they are tougher than you might think (for real commercial manufactured panels). Harbor freight panels I wouldn't bet on.
I've heard of people covering them, but if you have 10kw, that starts to be a big job.
ETA: The glass on them isn't like regular glass. I don't know if it's a low iron mineral glass, or tempered, or what, but tough.