Luna has excellent food. I've always had a good time every time I've been. Dinner is tapas and various entree's - it changes regularly.
I've only gone when I expect to spend a good deal of money, but I've always found it delicious. I prefer to go for the chef's choice special when I can. Less decisions for me and a wide variety of good tapas.
I've also been for lunch - its less pricy but still delicious. I didn't expect to be wowed, but I would say their lunch hamburger is the best in town.