We usually try to eat as both, seeing as how they're our favorites. We used to love Brown Derby, but it's gotten even more expensive in the past 5 years, and has some food that even my Dad, a world traveler, will not touch.
PT50's - if you want, go early and ask Auntie Whoever at the desk to seat you in a section with a waiter/waitress she knows will be fun...the lady last time told us it was great that we wanted her opinion and she sat us with one waiter, back to back sections with his best friend who basically gave eachother crap the entire time...we were laughing so hard we were in tears.
Side Note: Food, not the greatest, but dessert for kids is great.
Sci-Fi - There's nothing like seeing the kids' eyes the first time they walk into that restaurant. And them sitting in the car is hysterical to watch. But it's true - harder to communicate and control the situation when two or three are in front or back, and Mom and Dad are in the middle. If you do go, and the girls are a bit rowdy, get a "car" that's actually a table. If they're good kids though, nothing to worry about. Get a car :~)
Side Note: Food, also not the greatest. The two places are meant for their atmosphere.
Have a great time - you know your kids best, so asking them seems like a great idea! HAVE FUN!!
~Amy~:wave: