really depends on the cost differential. GT engineering is preferable to UF engineering in most cases, but no one's going to care 5 years after you graduate. the only difference really comes in with recruiting, and UF engineers do just fine. i can't speak for recruiting at GT, but i'm sure its as good or better (for engineering).
is it worth $20k more to go to GT? probably not. especially if you haven't even visited and don't know if you'll like it there in the first place.