Service can be hit or miss, but the food is always good. The people are always super friendly, but service can be slow. Price, quality and serving size are all in line here. The atmosphere is really laid back, with the occasional "fun loving" crowd at happy hour. Cuco's is actually a great place for a family meal and they do really well with small kids.
Free bottomless chips and salsa pretty much gets any restaurant off to a good start in my book. Margaritas are on par with your typical Mexican place. My experience with main courses here is pretty limited as I really enjoy the pollo fundito and pork burrito el roqueta. I have a hard time deviating from these favorites.
I wouldn't go in expecting a life changing meal, but this place is a really good local Mexican restaurant with friendly staff, good food and a laid back atmosphere.