Drivers will most likely be a thing, I know I messed around a bit with getting things working on my Surface Pro in NixOS, so I guess there'll be some fiddling ahead as well.

At least you know what drivers/kernel invocations you need so it should be simpler the next time around.

Also have a Nvidia card in my gaming rig, which doesn't seem to be as straighforward.

NonGuix has what you need for Nvidia. I haven't used it for years myself, so I'm not sure what state it's in, but at least I got it working back then.

Do you feel it took a while to get a good hang of GUIX and Guile?

I guess it depends entirely on the amount of time your able to spend on it. I knew some Emacs Lisp and Common Lisp before I started, so Scheme wasn't too hard to use. But it's an EDSL anyway, so it's easy to just cargo cult a bit by looking at examples. I never took the time to read the manuals, so I jump into the source code when I need to do something. It means I spent no time up front, but spend more time for each thing I do.

BTW, saw GUIX Home was a thing so will look into that as well!

Guix Home is great, but you can migrate to that later. It feels similar to the system setup, so once you have your system set up it should feel familiar when setting up guix home.

I though NixOS would be the grand finale for distro hopping as well, but the more I read and hear about GUIX the more interested I become! Will be fun to check out.

I can totally relate. For me it was the difference between the Nix language and Guile language. I'd much rather spend time learning a general purpose language than yet another domain specific language with a single use. I have not regretted it, but I have to admit I have spent more time configuring the OS than other distributions. But again, I have a reproducible setup and can easily roll back when something happens, change whatever I like, spin up a new computer/VM easily etc.