Hmmm...well, Charlotte is icky, in my opinion. The traffic is horrid and it's rather expensive to live there (same with Raleigh, though). If I had to choose, I suppose I'd choose Raleigh, but I'd live further out in Cary. The key is to find somewhere to live that'll keep you off I-40 as much as possible. I think the best parts of NC are at the ends -- the coast and the mountains. If I were moving back, I'd head straight to Asheville, no questions asked.
Any particular reasons why your mom is interested in Charlotte and Raleigh? Is she in the medical profession?