I haven't been on the
DCL Western yet but I'll try to help with the dining rotation question.
The dining rotation is based on three restaurants and two seatings for dinner.
Consider that there are 3 restaurants for each seating, so one third of the people for each seating time will have to be assigned to eat in one of the restaurants. DCL generally assigns people to a rotation based on the characteristics of the members in their travel party. I'm not clear on all of them, but for instance, we travel with just the two of us, so we're an adult couple with no kids. We always select early (main) seating and on four DCL cruises, we have always been assigned the LAP rotation. Except for the last cruise, we have always been seated with other adults without children. On the last cruise, we did have two kids at the table and I believe it was only because of balancing out the tables. Other parties with a different mix will have other rotation assignments.
It's up to your own personal tastes, but people consider making reservations at Palo's on nights when they consider their dining room or menu to be less interesting. My DW and I consider Parrot Cay to be the less interesting dining room, so we try to eat at Palo's on one of the nights we'd be eating there.
If you don't particularly care to 'dress up', you might consider eating at Palo's on a night when you would normally be dressed up anyway, such as Formal or Semi-Formal night, or a night when you'd be in Lumiere's, where it is usually 'jacket recommended'.
If you don't consider Animator's Palete to be interesting on a non-show night, you might consider Palo's then.
If you don't like Parrot Cay on the non-themed night, then that would be a good night for Palo's.
Other times, you just have to settle for a reservation in Palo's whenever you can get one, so any night will do.
hope that helps
