We were just there last week with my 3 sons 9, 11, 12. I was quite disappointed, even though we'd been there previously. We waited a LONG time, even though we had a PS and the park wasn't that crowded. Then the service was very slow. It was frustrating because the couple behind us in our car was seated well after us, and had their food before we had drinks (same waiter). I ordered shakes for the boys (2 vanilla, 1 strawberry), and got 2 chocolate before the waiter again disappeared for 15 minutes. We didn't know if they should drink them - we didn't, but the whole point of ordering them was to have them then while we were waiting. The waiter acted like it was our fault, and then brought 2 vanilla - again no strawberry. I was getting frustrated by this point.
My boys got hot dogs, which were extremely greasy. The kids meals came with very tiny drinks, and since we never saw our waiter, we never found if they could get refills or not (which they all really wanted). The waiter did push the glow cups on the first trip ($6 plus drink cost!), but we passed.
I was also a bit annoyed by as people said, the lack of conversation. If your kids are older, like mine, then they'll sit eyes fixed at the stupid stuff showing on the screen. Since I was there myself with them (DH was at a conference), and had no interest in pseudo-gory-cheesy Sci-Fi clips, I really had nothing to do other than consistently remind them to eat once we got the food.
We'd been there in the past and I thought had enjoyed it, so the server may make a big difference. Also, since DH was with me the other times, maybe I enjoyed the kids being zombies so he and I had a chance to talk. But it is loud, the food selection isn't very good (check it out before you go on allearsnet.com) and your parents especially might not like it too much. You can fit 7 in a car as folks mentioned if one can be in a high chair or 3 kids can squeeze together in a standard booth size chair.