This is not Mexican food. The food at Carlos O'Kelly's is at best a "take-off" of Mexican food. The food simply doesn't have much flavor. The menu is quite limited. And on top of all these reasons not to eat at Carlos O'Kelly's, the selections are significantly overpriced.
The atmosphere is about average for a typical American restaurant chain (similar to Applebee's and Red Lobster). Neither cozy nor comfortable. And of course, just like the food, you won't find any Mexican employees either.
If you're looking for Mexican food in Cedar Falls, go to Los Cabos on Main Street where they have excellent choices from Jalisco, Mexico as well as a "terraza" for outdoor dining in Cedar Fall's quaint downtown. You might also try El Mariachi on College Street where they'll give you an extra dose of tequila in your fish-bowl-sized margarita. Both Los Cabos and El Mariachi are owned and operated by very friendly, sociable Mexicans.