We went last year, the first week, it was over Mother's Day.
It was a good, low crowd time, we didn't have too many lines, except on Mother's Day, it was pretty busy that Sunday.
The hours are shorter, and there were lots of things in refurb, or closed,that may have been because we were also there for the premier of the POTC movie.
The weather was beautiful, we are from snow country, so we were mostly in shorts and shirt sleeves all day, even in the evening.
We didn't get fireworks, because they only happen on the weekend, and wind caused them to be cancelled.
I would go again that week, as long as there was no extra stuff, like the movie premier, that closed a lot of one area.