I believe that this has a good deal to do with the species that you're hunting and how pressured they are. I hunt Merriam's in the west and a lot of the turkeys I hunt don't receive the pressure that some of these Eastern populations receive. Therefore I really like a box call because it reaches out there and oftentimes our toms aren't too shy in responding to yelps from a box. However, for pressured turkeys when soft, quiet, infrequent calling is the ticket, it's pretty hard to beat a pot call. I suspect that if we all reposted on this topic along with the species we primarily hunt that most of the Eastern hunters would prefer pot-style calls and most of the Merriams/Rio hunters would prefer box calls but this is just a guess?? As previously stated, a versatile selection in the vest is still the best.
I don't have any experience with Osceolas or Goulds so no thoughts there. . . .