Last week I got in line at 8:35 am and was the only person in line until 8:45. between 8:45 -8:50 5 families joined in behind me.
For me, it was worth it to be the first family. There is always something special she does when you're the first family. Hide & Seek, personal archery lesson, etc...we've seen a few.
IMO, it's worth it get a breakfast waffle from Sleepy Hollow to get there about 8:30 am. If you have another adult with you, have them take the kids over to tea cups, philharmagic, carousel, etc while the other adult waits.