I have made a 9.30 pm reservation for the California Grill. How does Disney handle the Restaurants late at night. Will we be rushed to leave early or can we leisurely take out time and order a appetiser, main and dessert?
You will be given plenty of time to enjoy your meal.
Wait staff will not be visibly cleaning up or hovering near by, hoping you get the hint.
Relax. Enjoy.
They'll treat you just as normal. It's really nice to have a later reservation, especially at a park. Sometimes you'll wind up finishing and the park will already be closed which is great!
...DO look at Park closing times, so you can get an idea of when WDW transportation shuts down. It's not the end of the world - it just means a cab back to your hotel.
We personally like to take the scenic route back to our resort after a late ADR (restaurant/resort to DTD to our resort). Yes it is longer, but it gives us a chance to digest a little bit.
My wife and I (no kids) much prefer the last ADRs of the night and have never felt rushed, either in a park restaurant or a resort restaurant. In fact, we have had quite the opposite experiences in the past. Often times we have had servers and/or chefs chat with us for a bit after our meal. My wife has a tree nut and peanut allergy, so the chef that discusses the menu with her usually comes back out at the end of our meal, just to ask her how things were, but the conversation usually goes on for a while.