The Rockets will participate in the Orlando Pro Summer League, but until recently they were still weighing the possibility of playing in both leagues.
Part of the reason they ruled out Vegas is due to a scheduling conflict. The Orlando League ends the same day the Vegas League begins, and due to a new playoff-style format in Vegas, it is required that teams be there from the very beginning. It was still possible, but less feasible, for Houston to do both. It also may not hurt that the “Disney” environment in Orlando likely offers fewer distractions than does Vegas. Greg Smith, for example, was sent home from Vegas in 2012 after showing up late multiple times (practice and a bus).
The main difference between the two leagues is that the Vegas Summer League is open to the ticket-buying public and runs almost twice as long. In Orlando, only basketball personnel and media are allowed in to watch. That’s a loss for Rocket fans who travel to Nevada to watch the team (RocketGirl had some great daily recaps of her experiences at last year’s games).
Other teams that are expected to participate in Orlando include the Magic, Jazz, Nets, Thunder, 76ers, Celtics, Heat, Pistons and Pacers.