We have been on seven cruises and with six different cruise lines. Our experience with the treatment food allergies and gluten free needs has gone the full range.
We were treated very well. My wife has gluten free food issues and the sensitivity to her needs was consistently at a very high level. It did not matter what dining area we were in. From the Mater De to the dining room manager to the table waiter and his staff - all were involved and cared.
The excursions were weak, but conducted professionally. Some of the buses used were not very comfortable.