I've tried both. I was using stow before I switched to nix (on mac) and nix-darwin + home-manager. I use home-manager for everything except my vim config (I don't want to bury it in nix config and loose portability). home-manager is very nice when you want to create configuration that depends on other programs, e.g complex gitconfigs or crazy mutt setups.

I'm not sure if it's all worth it. I recently got a new machine, and it sure reduced the pain of setting it up. But I get a new laptop every four years or so. Bike shedding is fun.

home-manager is how I'm getting into nix. Having generations for my dotfiles is very appealing. Maybe I never really got the hang of stow, but I would also get bitten by it when I would rearrange my dotfiles, which would leave dead symlinks around. Perhaps this is what "unstowing" is for?