No, I don't change my mind as things go along. If I say something in the beginning I mean it still, unless I say later "I have changed my mind".
When I refer to "great service" that to me generally impies the waiters and housekeeping (to a lesser degree).
I don't generally put "guest relations" under service because I expect them to be flawless, and I rarely mention them unless they are not.
This was one case where I had an issue with them (and another I haven't even gone into, but something of a special circumstance). I know some people seem to get into it with them on every cruise. I am not one of those people. The only other time I ever complained about guest relations was on Mariner of the Seas - another story.
I still think this ship had the best food I have had since Crystal, and while Crystal was better overall, I had the singular best meal ever on this ship in Prime C.
I just wanted to point out that to me getting your money's worth out of a cruise involves a lot more than just good food. It involves their ability to execute your special requests (which are not "special" - they are what you paid for).
I have also had issues with some maitre d's and special dining on other ships, and I have learned it is best to handle these things directly as you suggest. Sometimes I learn by experience, and obviously for me - it was just my turn.