I've been using their DNS (and CDN) for a good while. Only positive experiences - fast & rock solid. I would start a new project with them again in future.

I've also tried some of their new more experimental stuff (magic containers, edge scripting) and it's much rougher, but the core product is very good imo.

I wish they'd focus more instead there tbh, there's plenty more that could be done in terms of core content delivery, without trying to enter other (very competitive & I think much more complicated) markets like serverless hosting.

I've been using their DNS (migrating away from Cloudflare) for over a year and I've found it solid. Good latency and fast propagation. Custom nameservers are easy to setup. Migrating from CF is easy too - just export your zonefile from CF and import it to Bunny and you're good to go.