I use them as my upstream DNS provider for pihole. I've only run into a few cases where I've had to switch to something else because their anti-malware DNS results was overzealous. I don't recall the specific cases.

I use it too. It's pretty good. Despite being relatively unknown, there's some big partners behind it like IBM.

I was using Quad9 until they had infra issues where latency skyrocketed from ~40ms to an unstable ~250ms... soon after I noticed that the routing was changed to another country with a latency of stable ~70ms.

A DNS resolver in another country breaks several things for me such as Wi-Fi Calling and certain CDNs that do not support EDNS Client Subnet, so I'm using Cloudflare Gateway DNS (DoH) for the time being.

Yeah, DNS over TLS using unwind on OpenBSD - never had any problems with their service.

Have been using them for years, never had a single issue.

Using them since they started. No issues.

Yep for everything, since ~5 years.