Well, let me give you my take. I lived in Alpharetta for two years and just recently moved back to CA. I was in the Windward subdivision. I'm not familiar with the development you mention.
We had 2 and then 3 kids
there. I think overall, it is a very family-friendly area, lots of couples with kids. My wife stayed home and had no trouble finding lots of other stay at home moms to make friends with. We found the schools excellent, in fact I like them a lot better that the school area we are in now in CA (which is supposed to be one of the best).
Also, it does seem the area has a large number of transplants. In fact, we had a hard time meeting anyone who was from the area. Almost everyone we knew was from elsewhere in the country. Overall, I had no regrets at all and I would still be living there happily if my job did not transfer me out.
I will say this though, there are tons of other areas to consider. Many areas of Roswell are nice, and you might want to investigate Sandy Springs and Dunwoody if you want to be closer in to town.
I guess the negatives are you will be farther from Atlanta, and the area while nice is not a prestigious as Buckhead, if that matters. It's more of a strip mall/typical suburban existance, you don't have the resturants and interesting shops Buckhead has. Just depends on what you want.