I live in the DC area (northern VA) and am somewhat familiar w/ Charlotte (wife lived there) and have been to Detroit (and it's surrounding areas) for business numerous times. Although it's been a decade or so, I have done business in Houston to have some familiarity. If you take everything (job market, weather, amenities, etc) into consideration, there is no question the DC area will come out on top. In a nutshell, MI weather is something to get used to. Houston is just sprawl and miles of concrete. Charlotte may be a close 2nd because of the climate but nothing really compares to the stability of the DC job market and the amenities it provides. Yes, traffic is horrible depending on your commute but you can mitigate that. You also have to get over how expensive it is to live here (but your salary should be higher to help).
Back to cycling, great group of people here w/ plenty of places to ride. If you are willing to get in the car, you have unlimited roads, terrain. Just note that it's not flat like Florida. Happy to answer any questions.