As for reliability, if you lose access to your "professioinally-configured endpoint" you're SOL. You can't do lookups (assuming you don't know how to do them by hand). Meanwhile I'm unaffected.
I would not have done this for myself and tell you about it if it wasn't faster. I'm not gathering info on users or selling anything. I'm not telling you what to do proclaiming I'm an "expert". I'm just an end user, like you.
When you use an open resolver, you are sharing a cache with everyone else who uses it. Some might do nefarious things to the cache.
When you use a resolver listening on 127.0.0.1 you are sharing it with whoever can access localhost on that port. i.e., no one (hopefully)
"professionally-configured" C'mon. You sound like a marketer's dream. Be a hobbyist. Be a hacker. Experiment. Thinks for yourself. Or don't.