Some additional points I'd add...
There is a strong christian perspective in Dallas. If you're a christian this can be a great place. If you're not, you just have to work a bit to find a group that aligns with your beliefs. The metroplex is HUGE so everything is here... but west and east coast liberalism is in smaller pockets and locations... general christian views are everywhere. The poltics certainly trend towards conservative (unless you're in certain pockets).
It's hot but generally it's not so humid. You need a strategy for the heat. It's very simple... get out in the heat early in the season so you acclimate. If you hide in your air conditioned house the first month you''ll hide all summer. Also get a house with big trees (if you can.. tough in the new suburbs)... they cut the temperature by 20+ degrees. Sitting in the direct sun of summer is staggeringly hot (i personally can handle it but most can't). Sitting in the shade of a tree makes it a completely different experience. I *strongly* recommend going to the Dallas Arboretum to see what a true Dallas summer is like when you're under trees. Also, pools can really be a great thing to have to beat the heat. lastly there are LOTS of lakes... I've been out sailing on the water on the hottest days of the year and never realized it since I'd just hop into the water whenever I got warm. If you don't have a strategy and buy a low cost (less insulated house) with no trees in a stark suburb with no pool.. you WILL find it too hot.
There is a TON to do in Dallas but the culture is more about going out to eat and hanging out at your (enormous) house. If you choose to go out, there's amazing entertainment for cheap. If you'd rather stay in your house, swim in your pool, chill in your home theater room, cook in your huge kitchen, ... lots of people do that too.
You can get anywhere in 8-12 hours... Sounds like a LONG drive but you'd be surprised how many Dallas residents go snow-skiing in Colorado and New Mexico. The 2 airports here are great too... if you shop deals, ski trips and getaways to Cancun in mexico are very very cheap and very common.
Most people are quite friendly and considerate. Some aren't but they stand out.
My biggest warning: beware of house A/C bills and property taxes... the nice communities can have 2.5% property taxes. A large house can have an $800 utility bill. Most people buy a LOT of house and then get shocked at the $8-12K property tax bill and the $800/month electricity bill.
Also the 'hip' parts of down trend towards private not public schools... the burbs mostly have great schools. If you live in the cool part of town you'll pay 50% or more for your house and you're likely to do private schools (some exceptions). the burbs are cheap cheap and good schools.
This is offset by no state income tax... but a smart play is a smallerhouse with full trees and a lower cost. You can save a LOT of $... of course a huge new house in the burbs is a lot of fun too 
... but it can be relatively more expensive...
Oh yea.. the storms here are legendary... I personally LOVE it... but get ready to be amazed by the universe when the 60 MPH winds and sheeting down water comes down almost horizontally.. only to blow away 2 hours later to sunshine. Wow.
All in all lots of choices....
Feel free to hit me directy if you want more details.
zb
