Great analysis of your visit to Dallas. I have a few things though I want to add though.

First, Nichols Hills and HIghland Park don't really have a lot in common. The scale and density of homes in Highland Park totally dwarfs Nichols Hills. The infrastructure in Highland Park is also incredible, as opposed to the poorly lit and pothole infested Nichols Hills.

Secondly, it leaves me shaking my head when you say that OKC has everything Dallas does but on a smaller scale. I don't think that is the case at all, at least not yet. You could say the opposite - that Dallas has everything OKC does on a larger scale and that would be true. OKC is still very reliant on Dallas and people flood down there every weekend because it offers so much that is unavailable here. From shopping to entire cuisines to their transportation network to museums and tourist attractions, Dallas is on an entirely different level. I hope some day OKC outgrows some of its reliance on Dallas in the same way Charlotte has outgrown reliance on Atlanta.

In terms of shopping centers and grocery stores, there is no reason OKC couldn't have some of what Dallas does, but it doesn't yet. The much higher number of grocery stores per capita there is the magic of increased competition, less Wal-Mart saturation, and modern liquor laws that make it easier for grocers to turn a profit. As for shopping centers, it would be very realistic to see development in OKC similar to the area in Frisco around Stonebriar Mall.

Lastly, people in OKC like to complain about Dallas traffic but for a major city like that, it is actually very navigable. Every time I've dealt with the supposed terrible traffic I have been underwhelmed by how bad it actually is vs how bad people say it is. It's all about perspective though. I know plenty of people from rural areas who complain about OKC traffic. If you are used to Houston or LA you would probably really appreciate Dallas traffic. Even smaller cities with less than adequate highway systems like Austin or Charlotte have worse traffic than what I have encountered in Dallas. Despite what people say, Dallas' investment in its highway system has paid off.