The food and service are good.
I don't remember how long our dinner there took this last Sept.
I am sure it was under an hour, but by how much I don't know.
It was just hubby and I. I would let your server know when you need to leave so they can do what they can to get you out the door in time.
Also leave time to catch the monorail. You might have a few minute wait and if memory servers you will ride from the Poly to GF, then on to the Cont. (does the resort monorail stop at MK? can't remember).
There were few items on the menu that made us make PS Ressies at Kona. I was glad we decided to do it, we are adding it to our list of must dine at places in WDW. Plus its usually not to busy.
Enjoy your dinner and Cruise!!!!