"RCI" limits the perks we can give you (legally) based on fare paid. This is due to their uniform pricing policy but even before we got our franchise, I was a customer with a T/A from the same company. Since most cruise T/A's don't add "garbage fees," I still think a T/A will do more for you than the cruise lines.
IMHO, a good T/A will always check for price reductions right up until final payment.
Hope you get some more postings so you can make an informed decision, Robbie