It really depends on the diver and the specialty. Night, for example, in Dive #3 has 3 mins of lights out. That is really difficult for some folks (monsters in the dark...) so the full specialty really helps them get over a personal hurdle. Search and Recovery is pretty good on dive 31, but some really good techniques and practice occur on dives #2 and #3, and it all comes together on dive #4. It is a terrific specialty, with real skills, but is time-consuming and tiring to do and to teach, and can't be done well everywhere.