My DS chose the Sci-Fi for his 9th birthday this past May. He loved it!! Sitting in the car was very cool. Our waiter gave him a 'drivers license" to keep. After dinner, they presented him with a very large and messy sundae with a candle in it. Our waiter also gave him a cordless phone to listen to...it was a birthday wish from Goofy!
We didn't think the food was that bad. After reading many reviews regarding the quality of the food, we prepared ourselves for the worst. Honestly, the food wasn't terrible. It's not gourmet, but it is certainly edible!! My dh had a rueben (huge!), I had a chicken sandwich,and my boys both had burgers and milkshakes (the milkshakes are incredible!!! they ordered a cookies and cream shake, and split it. Next time they each want their own! LOL)
I would offer your DS a list of options and let him choose. I did that for my son, and he was really stoked about going to the sci-fi while planning our trip!!!