For me, I really want to get into niri, but the lack of XWayland support scares me (I know there’s solutions, but I don’t understand them yet).
Also, I stopped using Emacs (even though I love its design and philosophy with my whole heart) because it’s very slow, even as a daemon.
My drive to nix was so I could simply manage what packages I had installed with a text file. If I removed something from the file, I expect it to be uninstalled. I never found a tool/wrapper for apt to do this.
If you want to start with nixos, I would take whatever distro you are on and install nix and then home manager. Then, you can slowly migrate your user configuration over without starting from scratch. That worked really well for me going from ubuntu to nixos.