I have so many memories of the Taco C in Waco. Back in the early 00s, when I was a student, Taco C and Whataburger were the only two spots for late night munchies after drinking. I attribute my 20lbs gained during college to their queso and tortillas.
The service in Waco has been horrible for a while but a big part of that is staffing. It has been very understaffed - I suppose because they've been underperforming financially- and it definitely created a frustrating experience.
It was very common to have only 2 people working - 1 person working the kitchen and order prep and the others taking orders at both the counter and drive-thru and also working order prep. That's fine until you have a line at both the counter and drive thru and the one kitchen staff is just trying to keep up with food. Everything else - the dining area, salsa bar, drink area, etc, all became unkept quickly because of it.
I stopped at the one in College Station one night at about 9pm about a month ago. There was one person working. One. I know because I asked and he was the only one in the entire building. Working drive thru, inside counter, kitchen, and prep. There were 5-6 people waiting inside and several cars in drivethru. I asked him if that was normal and he said it wasn't that uncommon. I gave the kid a tip and kudos. He was working his butt off.