With Konami having official Tag-Team rules (located here), the appeal of Tag-Team duels seem to be really enjoyable. Using decks that work well together, players would be more pressed to find new interactions between decks and archetypes that would normally never be considered due to inconsistency constraints. Burning Abyss and Monarchs would be terrifying because it provides Burning Abyss' access to a varied extra deck and an easy source of tribute fodder for powerful Mega Monarchs to take off, for example.

I've always wanted to try a competitive 2 on 2 format at locals, but nobody was really aware that a 2 on 2 tag team format existed. I think that Tag Team duels are a fun way to push the limits of decks, and to explore the numerous other ways decks and cards interact with each other.