Killeen has a reputation for lacking authenticity. Part of this goes with the transient nature of military towns. People see a bunch of chain restaurants and big box stores and cry foul.
But there are several dozen ethnic restaurants. Killeen has the 2nd highest Korean population in Texas. There are also German bakeries, an Asian market, and loads of community groups dedicated to the diversity the military brings.
I am not in the military nor did I grow up a military kid. But I did grow up overseas (Southeast Asia). I really enjoy the out of the way features of Killeen. Also, growing up as an American overseas I really enjoyed how quickly the international community assimilates people. When you are only going to be somewhere for a couple of years you learn to make friends fast. Killeen is really good at this - because its survival depends on it.
So you have a choice. You can look at the town and see all of the chain restaurants and big box stores. Or you can get a little creative and find the diversity and culture that makes Killeen great.