I recently spent a bunch of time comparing NextDNS vs PiHole. The reality is their features-sets are pretty close, but I eventually settled on NextDNS and here were some of my takeaways:
NextDNS Pros:
* Can use NextDNS on any network (thanks to their apps or just regular DNS-over-HTTP/TLS).
* (Could get similar functionality on PiHole with a remote hosted PiHole + VPN, but much more complex to setup)
* NextDNS allows for multiple different configuration setups per account (so you can fine-tune your blocking/filtering differently for different devices).
* (PiHole AFIK only supports a single configuration)
* NextDNS IMHO had the superior UI. With more powerful config options.
* In reality with some extra manual config/coding you could probably get PiHole to do most of what is in the config for NextDNS, but it would take some work.
PiHole Pros:
* PiHole is open source.
* The NextDNS server code is closed-source, but they do have an open-source CLI client.
* PiHole is self-hosted (much better from a privacy perspective).
* But you do get all the downsides of being responsible for hosting something as central as a DNS server yourself...
