...I would take your 4 year old to Seaworld. The only thing his height will allow him to do is Seuss Landing in IOA and the Nick Studios in Universal. There's a cool Barney show at Universal also, but you'll have to decide if you want to spend the money on just a few things between two parks. I could be missing a couple of things, but as I remember, my 7 year old neice missed height requirements on about 4 rides. SHE WAS NOT HAPPY!!
Go to Seaworld and give your 4 year old about 3 more years so he or she can really enjoy the Studios.
Our Dreams Unlimited Travel Agents will assist you in booking the perfect Disney getaway, all at no extra cost to you. Get the most out of your vacation by letting us assist you with dining and park reservations, provide expert advice, answer any questions, and continuously search for discounts to ensure you get the best deal possible.