When living in the school district that closed for the week, I actually did make two trips to WDW during the "dreaded" Jersey week. My own opinion is that a good number of people do go from NJ during that time, and it makes the parks more crowded than you might expect for that time of year. It was nothing like Easter week, but many go then expecting it to be dead and find it isn't so. Plus park hours were short as compared to the summer, so it compressed the people there even more. The weather was great that time of year for walking around the parks. As long as you don't mind being shoulder to shoulder with people wearing Bruce Springsteen shirts and eating salt water taffy!
Overall, if our schools now had that week off I would still be going then.