I think that air bed sofa GoPhoenix has is the only one PC ever offered with storage.
If you need a lot of storage, a couch can't compare to the bench seats of a dinette. But the dinette in many models require a no-slide-out situation. A dinette inside a slide out of a 2350 and 2551 will be very confining, so ridiculous that I wonder if Phoenix discontinued it due to customer complaints. But a dinette in the slide out of a 2351 and 2552 is quit a nice situation for the wall space is available.
In our older 2350, we have a dinette but we don't have a slide out so there is adequate wall space to accommodate it. Without the box of a slide out, the cabinets above get much larger. You get a glimpse of the over-head cabinets in this picture.

Decent Leg Room & Tons Of Bench Storage (no drawers, just big cavities)

Our dinette can't compare to the comfort of a couch for extended relaxation, nor accommodate for 2 adults sleeping, but it works better for the two of us considering the conveniences a dinette offers. The memory foam cushions we upgraded help immensely, and we are good at sharing the recliner behind the passenger seat. Everyone has their own priorities which is nice Phoenix accommodates.