So far I have to say that my nixos experience is underwhelming. Particularly the utter lack of any installer to make it easier to get started. Does anyone know of a nixos installer which can do EFI boot, FDE, LVM, etc. ?

I managed to do EFI and LVM but I did have to relearn the LVM commands to do it. Even a shell wrapper with dialog would be a vast improvement

Yeah, I feel like I've done my dues with linux-from-scratch so many times that I simply just don't want to do it all by hand, especially if it'd be over-and-over in experiments to find what I want.

Right, same here. It's the same thing that put me off trying Arch. That and both pacman and nix-env are very rpm-like in their usage :-/