I've heard of quite a few stories, but that doesn't give me the big picture..... There is a skew towards people coming here, and other social media, with issues/stories.
There is also the fact that the demo for class A's is a higher age, and thus less likely to BE on line.
So, no valid data for a conclusion.
I carry a spare belt and plan on changing the one on there at 50K (Halfway there in 28 months) at which time I'll closely check the tensioner and idler pulley. Any doubt I'll replace and carry old ones as spares.