Hi! We loved DQ and definitely thought it was worth taking a day to do. I would not skip one of the theme or water parks to go there (but my teen boys would!!!
).
We were there for opening one day (11am) so we slept in that morning and got a little rest. We usually try to do this about 1/2 way through our trip when we could use a break.
It's nice and air conditioned and there are lots of places to sit and rest (DH and I were able to do this while the boys played games). I realize you have girls and that they are younger than my boys, so you will probably be with them the entire time.
I thought the Create Zone was really great for families and we all enjoyed the Pirates of the Caribbean and Jungle Cruise games together.
We actually found the food at the Cheesecake Factory (inside DQ ) to be quite good. A very nice place to grab a bite....the desserts are wonderful!
As for restaurants, we like the House of Blues and it is right across the street from DQ. We also like the Rainforest, but it is at the other end of Downtown. Wolfgang Puck also has a counter service type place not far from DQ. We've never been able to eat there. We tried twice on our last trip and they were always out of something (pizza, chicken, etc.) and we were told it would be 45 mins to an hour before they had any more. It doesn't seem like they handle crowds very well there, so it might not be the best place to consider if you'll be there at a crowded time. This is strictly the counter service place, not the restaurant.
