We went to Rivas at 9:00pm the day before Thanksgiving. The place was clean and well organized. Some of the cool things are 2 TV's that had the Suns game on and the place was empty besides one couple. We had grilled chicken tacos, cheese quesadillas (delicious), machaca and egg burrito, chicken rolled tacos, and regular chicken taco. Honestly, the food was just average. The quesadilla was the best part and I would give that one item 4 stars. We didn't eat in the restaurant and they had our food ready in about 10 minutes which in my book was pretty quick. They had a large variety of menu items and serve the breakfast items until midnight!
If you are hankering for a quick decent Mexican meal this is your place. Still doesn't come close to Carolina's but I give it 2.5 stars for the food and 3 stars for the inside of the restaurant.