Rankings are good, but as we all know, one bad teacher can poison a child/family against a school system. This is especially true with Special Pops classrooms.
I was a teacher and school administrator in Raleigh, Cary, and Emerald Isle but now live in Wilmington (as a Realtor).
Good resource:
www.ncpublicschools.org
Many factors go into a school system's 'rank'. Dig deep to get the big picture.
Personally, I'd chose Wilmington over Cary in a heartbeat.
I hope this helps.