Being as you have only been to Dallas twice, I wonder how you formed these opinions. Especially the comment about Fort Worth. Having grown up in Fort Worth, I must wholeheartedly disagree.
The downtown area maybe underutilized. And with downtown and the lessor desirable parts of the city right off 35W appearances may not be the best. But it is no worse than 35 South of downtown San Antonio.
Also one thing I have not seen mentioned here is allergies. If you have bad allergies you might not like Fort Worth. If you don't have allergies, you will when you get here.
And on a, not meant to be related note, Fort Worth has a great Zoo.