Posted something similar on the NixOS sublemmy, but it basically boils down to the fact that I tend to switch back and forth between both distros, and I enjoy both very much as both Gentoo and NixOS provide an immense degree of control over my system and allow me to go wild and do whatever I want. But I feel the need to settle on one system and tinker with the other on a VM instead, as this switching back and forth is becoming a time sink and hindering my studies somewhat. The question is, which to use as the main desktop system? Gentoo feels more intuitive to me, but NixOS is definitely powerful at managing complex systems, but then again, I only have a simple desktop system. Another thing that I thought of is that maybe I can somewhat replicate NixOS' rollback feature, which is my absolute favourite feature of it, using a combination of Git and ZFS snapshots? I'd like to hear your thoughts on this.
Never used it, but yes, appears to be so. Another option is unRAID.