I don’t really have a choice in the matter: most software is written for GNU/Linux systems, which is Unix-like at best. I agree that Linux has had many improvements since then, and I wholeheartedly support and applaud Linux for what it has achieved as a project.
If there was a usable Unix derivative (different from *nix clones) I would seriously consider it, but I don’t think there’s much development other than AIX and what was Solaris by Sun.