I have no particular opinion about this, but:
Some people used to really hate the idea of adding recording-level DJ mixer rels unless the specific track/recording was itself the whole of the DJ mix, since what's DJ-mixed is the group of tracks rather than one specific one. So they'd definitely say "use the release one for DJ-mixed releases, and the recording one for things like a one-hour-long DJ mix at the end of a compilation like the ones they sell on iTunes sometimes".
Other people said that that was stupid, that there's no way to mark a DJ-mix that takes most, but not all, of a release unless you add the rels to recordings, and the like.
Pick one opinion, I guess