Not all Roberto's are equal. . there is another one close enough on Gibson where you can just pass this location by. Why you ask . . . . very simply:
1. They charge for refills on drinks - others do not
2. On $1 taco Wednesday, the only do this for the hard shell taco. Other locations let you have the soft tacos also for $1.
3. The taco's here are GREASY and don't taste the same as other locations. The hard taco was more like the type of taco you'd get at Jack-in-the-box where they deep fry the taco in oil with the meat inside. I've NEVER had something like this from a Roberto's.
It appears that things are slipping a bit and the lack of attention is hard to ignore. Maybe you expanded too quickly and simply can't "police" your own locations. Time to hire someone to pay closer attention to the details.