Cantina Laredo is pretty big and even though it is popular, the majority of the times that I have eaten there I haven't had to wait for a table. However, they do have a large bar so if you do have to wait that would be a good way to drink the time away.
I nearly always opt for the guacamole appetizer. There is no way to complain about guacamole that is made tableside. If you don't like cilantro - tell the friendly staff not to include it in this awesome dish. If you're sensitive to heat they'll leave the jalapenos out for you too. However, I like my food really spicy so I make sure that I get all of the jalapenos that are available. When it's all said and done, this guacamole is good. It's just good.
In addition to the guacamole I am also a big fan of the Monterrey enchiladas. The mole sauce adds some variety, and the spinach enchilada helps me fool myself into believing that I am eating healthy.
The wait staff has also been consistently friendly. When I have eaten here the food has come out quickly, and my drinks are regularly topped off.