The word I would use is unremarkable. My husband has coerced me to go to Cuco's three times now and every time has been just ok. Not good, not bad, just...meh. I would never choose to go back on my own that's for sure.
I have had chicken enchiladas, shrimp "cocktail" and some burrito. All were mediocre. My husband gets the burrito cucos and loves it. My 2 year old son loves the chicken enchiladas and refried beans...then again he eats crayons so you might not want to trust his palette lol!
If you are looking for passable Mexican food you'll be happy. If you're looking for more, perhaps you should pass on Cuco's.