To my knowledge, that is the only on road track in Orlando. I've heard of one in Daytona, and one in Tampa. But haven't made it out to either yet.
As for off road, there is one off east 50 in Bithlo. At the orange county paintball located on cr 13.
There is also another one out in Clermont. It's about 30 mins to an hour away, depending on route, traffic, etc.
Both tracks are fun. The one in Bithlo does not have organized racing, the one in Clermont does.
Sorry I don't have more info. If you hear anything about more on road near Orlando, please let me know. I generally work the first Sunday of each month, and so have never made it out to Superior for their race day.