X_A,
Sorry for the late reply!
I have some positive things to say about SoonerCon in general: the event was held in a nice venue, the organizers seemed interested, and there was some effort to promote Pathfinder play. The con was not nearly as busy/crowded as expected. I was unaware that there was a cosplay component. It appears even the cosplayers were caught by surprise -- there were less than twenty entries into the costume contest.
Some observations: the gaming area was not run by event staff, so it was largely "play where you can find a seat". Again, my interest is in Pathfinder, so I was disappointed that some of the games were homebrew rather than Pathfinder Society-sanctioned scenarios that afforded advancement opportunities for my character.
I am a very outgoing, extroverted person so I made efforts to enjoy myself and find things to do -- people who are looking for programmed/scheduled activities would find it difficult to participate.
I believe it's a worthwhile event to attend if you live in the Oklahoma City metro area, but would not consider it to be a "regional" con that would provide enough to justify a three-day hotel stay.