Yep, we are. We're going for 9 nights.
Honestly, going for 8/9 days, you'll have more than enough time to see everything in the 4 major parks - probably more than once. I won't mention any "don't bothers," as everyone's taste is different, and most attractions and shows have something to offer, but I'd say a few definitely "do not misses" are Test Track and Soarin' at Epcot Center; Space Mountain, Splash Mountain, and the Haunted Mansion at the Magic Kingdom; most of the live action shows at Hollywood Studios are exciting and interesting.
Every few years or so, my wife and I go down there for 3 days, and we have enough time to fully cover all the parks. Although we usually go in winter, so the parks are less busy than they are in the spring, you should have no problem seeing everything you want.
We stay outside the park and rent a car, so that we can go between parks easily. If you're staying in the park, I'd suggest not travelling too much between parks, as their interpark travel system can eat up a lot of time.
Also, use FastPass. It doesn't cost more money - you simply pick up a ticket for a particular ride for a later time. This allows you to not wait in line, and simply go to the ride when it's your time. This will save you a lot of time - particularly with popular attractions. I'd suggest picking up FastPass tickets for popular attractions as early as possible in the day, as they eventually run out.
. Tower of Terror is good so is the aerosmith one. Epcot is really cool and has lots of funky stuff. Animal Kingdom is fun as well.