Was the Salisbury Steak their in-house Kirkland Brand or was it served at their little "food court"?
The food court at their West Plano store rocks: a few really decent Mexican specialties, their chicken-in-a-crust thing, the usual dogs & Polish, so-so but generously portioned pizza, and ice cream treats. It's worth going to for lunch alone.
Recently (at that store alone of the three Costcos we shop at) they added Italian Gelato in three flavors. At $1.50 for three big scoops it's the best sweet deal in town. The same serving at one of our "chi-chi" gourmet gelato stores here in Dallas would be at least eight bucks.