Valle Luna can fill up quickly, so your best bets are to go around peak hours or perhaps week days. If it's crowded and you want less noise, ask for one of the smaller rooms. The dining room is compartmentalized into several sections of varying size. The dining room and restaurant in general are nicely decorated and not gaudy.
Chips and salsa are complimentary. The salsas are good, but not spicy. The chips are good, but I suspect they're just good quality packaged chips, so if you're looking for the thicker chips, this may not be for you. Try the street tacos. Those are well made. The spinach enchiladas are also well made with lots of cheese.
We also had a chance to visit the restrooms. They are nicely decorated and were very clean, despite the large crowd.