AOW is a different class from Primer or Fundies. For example, at least in the PADI system, you WILL do a navigation dive . . . most folks don't come out of OW with great compass skills, and having a chance to practice that a bit is often quite useful. You may also, if you choose, do a night dive, and Fundies must by standards be taught in the daytime.
In contrast, Primer and/or Fundies will focus very intensely on personal diving skills, especially good control of buoyancy, trim and positioning in the water. And the GUE classes will constantly harp on awareness and team cohesion and communication, none of which are necessarily addressed much, if at all, in AOW.
I don't think someone with a Fundies rec pass would benefit very much from a standard AOW class, but there might easily be specialties like Nav that would be quite beneficial. Someone who is asking if he has the experience or skills to do Primer or Fundamentals, though, might benefit considerably from an AOW class, with five instructor-supervised dives, especially if said instructor has some cave diving experience