Last year I gave Longhorn a try. It was a nice proposition for me: I was using local storage anyway, so the idea that pods would be independent of the nodes sounded delicious. Except the price was way too much.
At the time I thought that the only problem was Prometheus, which in itself is pretty heavy on disk IO, but it turns out the issue was with Longhorn itself. Also, as I found out, I wasn’t thorough enough deleting Longhorn stuff, which resulted in quite a few headaches this year.