In The Doherty Approach we think that couples bring a broader array of interactional patterns and outside stressors than current models emphasize--and that therapists need a way to prioritize what to work first, and then next, with multi-problem couples.
The Family FIRO Model does all of this. For therapists who love attachment, it's in this model in two places (basic connection vs the less frequent, vulnerable sharing of inner emotions.) Those who love differentiation will appreciate the emphasis on boundary setting and personal agency. (We don't let anyone mind read or speak for the other during sessions. Our approach also ensures both people are sharing agendas and that both sign up for looking at self.)
What's more, the model offer a way to trouble shoots problems in the therapeutic system of the therapist and the couple. A lot for one model to deliver, and we think it does.