I don't know if it's an obvious question or not, but how does performance compare with your own unbound vs quad1/8/9? I imagine it's slower in general?
I'm not personally running unbound, just a Pi-hole that up-stream's to my ISP's DNS, so I can't answer you from first-hand experience. But, according to drexlspivey, unbound will pre-fetch common queries, so it probably ends up being faster on average - https://news.ycombinator.com/item?id=30646020
I never measured anything, but i'm running a recursive resolver on my laptop since a couple years (knot resolver) and never had any performance problem.