I think that you are going during the famed "Jersey Week". We were there last year at this time. The weather was nice during the day, cool enough for jackets and jeans in the evenings. We were in the pool practically every day.
As for the crowds, it depends on when you are used to going. Some of the rides had really short waits (no longer than 5 minutes) while other rides had longer waits (up to 20 minutes). In Disney terms, these are short waits if you are used to the spring or summer. Remember also that the parks are closed a lot earlier than in the summer. I think this results in some of the longer lines.
We found it really enjoyable. So enjoyable that we will be returning this year around this same time. You will love it!