Not a fan of Pi-hole itself, but other than that,why not?

(Technitium DNS has some advantages down the road)

It's fine, did the job for me at the time. Just wanted the ad and nasty blocking. Keeping it and the filters up to date is easy.

Now have a pfSense box with pfBlocker-NG, which does essentially the same thing. Also runs Snort as an additional layer, and makes penning in IoT stuff possible.

I installed a Pi-Hole largely to serve as a local DNS, but enabled the ad-blocking 'cause it seemed silly not to. My wife got very upset. Apparently she likes the ads.

With that aside though, it seems to work quite well. Just make sure to (a) use a reasonably-powered device (my Pi Zero appears to be taxed by it) and you should probably use an Ethernet connection 'cause my Pi Zero regularly flakes out so DNS requests fail due to the IP being "unreachable" for a half second.

Anybody got the feeling some games may be negatively affected by a PiHole ?

It'd not really the reason I stopped using it but I suspected that some games didn't like it when PiHole was up...

Anyway this post motivated me to reinstall my RasPi.

Depends on how you do it and what you need from it. I've actually moved on from my Pihole instance, for reasons I'll get into later.

The broad appeal of using Pihole for DNS in a homelab is the ability to route services from domain names on the local host. This can be really useful, especially for "hacking" service availability onto other unintended devices. Additionally, it can be nice for less tech-savvy users who might not be comfortable editing /etc/hosts or just want to check out a service on their phone web browser.

I would generally recommend using an isolated device for Pihole needs; If you're doing work on your home server, you'll probably want all users on your service to keep their internet connection working to not be a burden to others living in your household (if you have others). A raspberry pi is a really good target for a pihole, and even a cheap old/used one from the interwebs can serve you well (I was using one recently on a pi3b and it was no issue.) Keep in mind that you can't really do fallback dns configuration unless you're ok with losing the key feature of pihole (blocking ads and redirecting domains). Notably, I'm actually not a proponent of running all services on individual compute units generally, I just think DNS is special and you don't really want to tie it into docker services to keep a separation between the services and the server, so to speak.

This brings me to the second feature: adblocking. This one is really a mixed bag. Ultimately, I turned this feature off only because it doesn't work for the websites that have arguably the most ad content (youtube, twitch) and really only serves to hurt the smaller players. Sometimes it's great for blocking things like SmartTV advertisements or data encroachments, but it's very hard to block ads from a web domain in a way that doesn't outright block the service itself (so blocking youtube ads without blocking youtube is, seemingly, a fools errand.) I'm willing to hear other people's opinion on this, I just couldn't get this working to a satisfactory degree.

I've abandoned Pihole as a local dns resolver. This is because Tailscale suits my needs and also allows me out-of-house connectivity to things like my music or personal data so my phone never goes out of communication with my home network. When you use tailscale at home, it's generally really good about routing that through your local network instead of the relay, so there shouldn't be that many downsides. Note, I say generally, because there have been times where it goes through a relay unexpectedly which I haven't solved yet (this is likely a local router configuration issue, anyway...)

I notice that you're already familiar with Pihole, but just thought that it would be best to "explain" my thoughts on it in the form of a recommendation/editorial form.