I worked across the street from a TDM and went there nearly 80% of the time I had lunch. I probably redeemed 8 of those punch cards, easily. I got to know the people who worked there (ever-changing faces). They were all pretty nice, though it is different from location to location. But wherever I go, they seem to foster a chummy environment. I'd say pretty good customer service, even when they mess up your order.
Pros: Value. Filling. Tasty. Fish burrito. Enchiladas.
Some cons: They act before they ask, which is typical of assembly line restuaurants. Their pico de gallo does bad things to me. They don't drain the meat enough before plopping it on your tortilla. Sogs everything up. They changed from deep frying to baking the tostadas resulting in less crispiness. Boo.
When I started to get sick of eating there, the meats didn't smell so hot to me. It reminded me of what it would smell like coming out. Then there's the same ingredients assembled in different forms depending on what it's called. Same old same old.
Basically, when they're good and you're in the mood for it, it's pretty good. But it's not anything worth craving and seeking out.