So I decided to give it a quick test on a RPi3 basically following
this guide. Note that Raspbian defaults to a UK keyboard layout and you can't enter a | character from the keyboard until you change it to a US keyboard by running
sudo raspi-config.
I didn't do a full network integration. I just manually set the DNS on one of my PCs to use the Pi-Hole instead of the router. It generally cleans up the web, but some ads on some sites still get through that would be killed by uBlock Origin if used. FWIW, they're not particularly flagrant ads from what I've seen so far. Pi-hole doesn't really help with excessive scripts either (though they don't claim to).
My initial impression after less than an hour of use is that you'd probably still want to run ad + script blocking on top of using the Pi-hole if that's what you've been using all along. Script blocking on top of it at a minimum. I don't really see it as a fix all. Especially not for a laptop if you take it out of the house and connect to other networks.
It also breaks things. For example, you can't watch full episodes on CBS's website when using it (you get an error message about the video being unavailable and playback won't start). uBlock Origin has no such issue. Playback starts and it prevents the commercials.
To me the biggest benefit I see is that the Pi-Hole helps reduce the ad load in browsers that don't offer ad blocking.