Personally I wouldn't go to either, considering I loathe large cities with a burning passion, but you seem kind of passionate about this so I'm guessing you prefer city amenities. Now having said that, all of the "perks" are basically identical. Texas and Florida are so similar financially they're basically twins. You won't really get any more benefit picking one over the other.

So at that point, it's a matter of climate and culture. Dallas actually gets cold beleive it or not. It's only a little south of Oklahoma. Snow is absurdly rare there, but it can, and does get cold enough to warrant a medium thick leather jacket in the winter. As for the culture, well don't expect any cowboys. Dallas is a financial hub, so imagine southern NYC (in fact I believe the NYSE actually considered moving to Dallas in 2020). Lots of suits, hedge funds, financial firms, etc. That being said, they do have a decent amount of entertainment, plus you can go an hour in any direction and find a more stereotypical Texas experience.

Fort Lauderdale is probably closer to Hawaii climate wise. Very tropical, hot, humid, moderate amount of rain, beaches, the Atlantic ocean, etc. Culture wise...... I mean it's Florida, not really sure how to explain that other than bombard you with Florida Man memes.

So at this point it's a matter of do you want to experience cold for the first time in your life, or basically have the same climate?