One person's opinion: If you already went to USF and were not totally thrilled, but you haven't been to Sea World, new is a good reason to go (beware the prices, though! I heard it's over $50 along with its sister park at Tampa.
I enjoyed myself there, and there are three rides there. I forgot the name, but there is a motion simulator that simulates a trip through the arctic that was nice excellent theming and animal displays afterwards.
Journey to Atlantis was really nice theming with a pretty nice ride (though one piece of theming doesn't really make much sense. I couldn't quite follow part of the story because the video came on before we got close enough to hear it.) Pretty unique at any rate.
Kraken is awesome. SFGAdv is my home park with Medusa as the floorless here and Kraken surprised me by having a pretty steep first drop, loops below the ground, and a nice view.
I had bought a two park pass at Busch Gardens, so it came out a bit cheaper for me that way, and the ski show wasn't bad either. Overall, I enjoyed myself, but the $50 price tag may just be too much. That you'd have to decide for yourself.