We are doing 14 day from Buenos Aires to Santiago. We have 4 sea days plus another 2 scenic cruising. We also have an overnight in Buenos Aires. I guess with the scenic cruising days I didn't think too much about all of the sea days (6 if you count the 2 scenic cruising days)
Deck 18, you access it through the Center Court. You needed to sign up at Passenger Services. I will note that we were in there in January of 2020, and I am not sure if they are still running it due to Covid as it was a small area.
We spent 11 nights on the Sky over NYE and the food was great, no complaints. We are currently on our first HAL cruise, and only 2 days in my husband is telling me that he prefers Princess.