Since the original 500's release I have never seen a single forum post (in generic tech discussions) about the product.
In other words, for me who spends lots of timing reading/watching discussions/reviews of gadgets, this never came up once, anecdotally.
I don't think you are alone in your confusion.
One has been sitting in my hallway closet running a pretty complex HA setup. It has been so rock solid that I more or less forgot about it.
But I assume that's not the pi 500? I mean, this series has/is a keyboard, and if you are just running it as a server, you save some money by buying a regular version
Yes, a Pi 500.