I ate at the Canonita for dinner with some friends in January 2016, and was not very impressed.
The restaurant is located in the Venetian Resort. The service was good. The decor/ambiance was pleasant.
I ordered the Chicken Caesar Salad for $15. The chicken was flavorless and chewy. I ate about a quarter of the chicken. I informed the waiter that the chicken was not very appetizing. I expected him to either offer another dish or to remove the item from my bill. He did neither.
I also had a Cadillac margarita for $12.50, which I thought was very good. My second drink I asked for the happy hour margarita for $5. I laughed when I got it, it's half the price, because it's literally half the size. Despite it's "short" comings, I thought that it was also very good.
In defense of the restaurant, all of my friends said they really enjoyed their meal and would come back. Maybe I just lucked out with my entree selection.
If you like expensive Mexican food, give it a try.