Lexington is an old money town with fantastic schools. (Well are the schools really that good, or is it just that the parents are all highly skilled professionals?) In any case…housing will certainly be more expensive than Wilmington. Neighbors will all be doctors, lawyers, executives. Wilmington more likely to have tech professionals with blue collar types mixed in. If money is no object, these are the towns with the best schools/reputation that are north or northwestish of the city in rough order:

Lincoln Weston Sudbury Newton Concord Andover Carlisle Bedford Acton Boxborough Reading Westford

This ranking is based on no particular evidence, just what I have picked up over 20 yrs living around here.