Completely different areas....
Coppell is small town....most schools excellent. Little real crime. Family friendly atmosphere. Mostly newer homes...last 15 years or less. Most homes $200,000 to $1mil, so mostly professional.
Dallas typically has older homes, different style, more one story, maybe bigger yards...huge city, probably less sense of community, but mixture of people in the neighborhoods.....Brentwood is great, but what happens after elementary, or the school closes, or zoning changes? It can happen in any city, but the way Dallas demographics are..../???
I've lived in both areas so if you want to sit down and discuss some of these ideas and more just let me know. Nothing wrong about either one, but to me very different....not even really comparable for most people.