I was testing out a bare metal install of pfSense 2.6.0 on my Dell Wyse 5070 and I noticed that the DNS Resolver was noticeably slow on certain occasions. So I ran DNS Benchmark and saw that it is indeed slower when it comes to uncached and dotcom requests. It's also reported to be not 100% reliable.
The image above shows 192.168.1.4 which is PiHole docker container that is using an Unbound docker container as its upstream DNS (running in a HP ProDesk 600 G4 i5-8500T). 192.168.2.1 is pfSense stock install running only DNS Resolver (DNS Forward not enabled).
Not sure if there are additional settings to configure in pfSense? Just seems kind of odd that it's slower. I would think that it would at least be on par if not faster than the containerized PiHole / Unbound setup.