Yeah you need to live fully if you have an identical relationship. Dual will insist you do stuff with them, so living/be with gets taken care of itself. But you have pure, bedroom understanding... but yeah, not much else. Which is fine if that's what you want in a relationship.

Identical is like, pure connection... but you kinda drown out too much of the outside world.

It's really the ONLY downfall though. Other than that, it's just as good as dual.