Some things to consider...
Chiming in very late here, but...
Remember that the '7 people capacity' is kind of more marketing fantasy than anything else. Take a REAL good look in that RV before you rent it, and picture everyone racked out and snoring. How's that going to work out? Two - three people in the rear bed, two people on the dinette, two on a fold-out couch?
And are you (and DH) comfortable with DRIVING and maneuvering Class A rig sized for 7 people? Think about driving through Chicago at rush hour - would you be comfortable doing that?
(Heard a funny story about ten years back - guy with no experience was thinking about getting an RV and hitting the road, so he sold his house and bought the biggest thing he could afford, a veritable palace on wheels. He drove it off the lot, made it to his first campground... then called the dealership to see if they'd take it back without too much of a hit. Turned out he HATED driving it. He mailed them the keys, told them where to find it.)
Also think about the logistics. The gray- and blackwater tanks on an RV will only hold so much - and if you're not used to messing with them it can be a bit unpleasant. (That said, the Disney sites are the best full-hookup sites I've seen ANYWHERE...) With 7 people, figure frequent emptying, and even the larger rigs usually just have a 10-gallon water heater...
If it all works for you, then happy travelling! But the point of a vacation is carefree enjoyment. (For most people, that is... some like a challenge. :thedolls:) If this will be your first time with an RV of this size, it may well not be carefree!
By the way, if you're coming through Atlanta, you can take the HOV/Carpool Lane down I-75 through the city. It'll get you through without being peeled off by the I-20 interchange about midway through, or the I-85 split to the airport.
Have a good vacation!