How about the weather. Yea, it is hotter than hell in Del Rio, but it is hotter than hell in OK too. In Del Rio, you don't have tornados like you do in OK.
They sell better beer in TX. You have Shiner and Zigenbock. If you want them in OK you probably have to deal with some bootlegger or some other low life that swam across the river with it.
Del Rio is close to the border. You can go across and do shopping. Stuff is cheaper there. Like cigs, and liquor, and taxed stuff. You could do that in OK too, but then you would be in TX. So why not just move there.
Del Rio is in southwest TX. The heart of deer country. The place is lousy with them.
They say the reason TX has not fallen into the gulf of mexico is because OK sucks so much.
Thats all of the reasons that I could think of at the moment.
John