Not true. You can write your own packages in the same high level interface. Including the mainline Linux kernel and broadcom drivers. I have GuixSd running on my 2013 MBP
can you tell me how you got that running in some more detail? I also have a 2013 MBP and would like to try out GuixSD
Here is a gist of the relevant packages and configs I have for my MBP.
For me, the problem isn't so much with the nix language(it's very similar to haskell), but the lack of discoverability for docs of library. The manual is mostly incomplete and i often have to look at sources. My most favourite thing is that i can just override the packages to compile and install a new version/extra configure flags of a package that's not yet upstream.
Interesting... I've found the manuals to be ok so far. Can you share what you've had problems finding?
Well, a lot of common functions like fetch* , write*, makeWrapper that are used in packages are undocumented. I usually dig into source files using nix repl to find the location.