it's a lot less scuffed in some ways while still giving you a lot of control and a lot of tools for declarative system management. it's also waaay better documented. it's comfy.

Why does every one need to compare every distro to NixOS? We get it. It's neat. It's immutable. It's indestructible. But they are fundamentally different stuffs.

Completely different -- nixos is about repeatability, while Gentoo is about build optimization, customization, and performance.