Just as good as the Don Tortaco on Eastern and Warm Springs. This place used to be "Taco Tio" which was an abomination of a taco shop. Don Tortaco on the other hand is one of the best chains in Las Vegas.
Carne asada chips are pretty much perfect. Good guacamole. Not too many beans. Competitively priced.
Quesadilla is one of the best I've had in Vegas. Very cheesy and very buttery. The tortilla could be more flakey though.
The last time I went in they were having technical problems with the cash register. I stood around in line for over 5 minutes without even being acknowledged. A simple "sorry, we'll be with you in a moment" would have gone a long way. I ended up walking out. Even with this bad experience, I'll still be back though. The food is that good.