The Dungeon’s Master home group currently uses a rotating DM system. Each of us takes a turn and as we approach the end of our segment we cue who ever is on deck to get ready to take over in a week or two.
The rational for this is that none of us has the time to truly run a long term campaign and it allows each of us to take a turn being the DM. As players we experience different styles in encounter creation, story telling and pacing.
The aspect I’m enjoying is seeing what everyone does with their maps when their shot as the DM comes around.