I stopped by both Tierra Caliente and Pasadita (the small GNR one) for lunch today. I was curious to compare the two and it had been a while since I'd been to Pasadita.
For the sake of comparison I won't talk too much about the pastor or birria tacos at TC since Pasadita doesn't serve those, but I like both of them better than the carne asada at Pasadita.
In general, the tacos are a much better value at TC. For two dollars, they over stuff the tacos such that every taco I've ever had there I had to finish off the spill over with a fork (or with my fingers). Pasadita's tacos are a little more than half the size of TC's and they cost $2.65.
The carne asada at Pasadita is more tender and it's better seasoned. On this particular trip, I'm pretty sure the meat came off the grill 10-15 minutes before it was served to me since it was taken from a steam tray so it was warm but not hot. Also there were very few charred bits, it was pretty much uniform throughout. The carne asada at TC is cut in much larger chunks and taken off the grill after you order so it has more crispy bits. The pieces can be chewy, and though the meat is flavorful, it was a little under-seasoned for my taste. The best bites were from the TC taco, but overall I thought the Pasadita taco tasted better.
The lengua taco is more tender at Pasadita and looks more like a tongue stew with large hunks of meat. It's stewed in a flavorful broth and exquisitely tender. The lengua taco at TC is grilled then cut into small bits. Once again the flavor is good, but lacks the zip that the Pasadita taco had. The difference between the two tacos was greater than I was expecting.
Pasadita has changed over the years. The interior has improved (no more decaying bar stools or cracks in the walls) and the prices have gone up. They still do a great job seasoning the carne asada, but I feel like they're no longer putting the care in to make a truly excellent carne asada taco. The lengua taco was a very pleasant surprise and I could see myself opting for that over the carne asada on future trips. In a lot of ways, TC is what I imagine Pasadita used to be like before they started expanding their empire (I only started visiting Pasadita about 3 years ago). TC specializes in al pastor and it really shows. Their carne asada and lengua are very good, but Pasadita has what I would consider to be better versions even though there is some room for improvement.