We decided to go to Delmonico's on the recommendation of my mother, who goes there every time she's in Vegas (every year), and my husband's company was picking up his share of the tab!
We made online reservations -- we initially asked for 7:00 reservations, but got 8:30 instead. Delmonico's is located in The Venetian, which is a sight in and of itself! We got to the restaurant early and sat in the bar area where they had a flat panel tv and we watched the baseball playoffs while waiting for our table.
The atmosphere is dark and romantic -- it very much seemed to be a place for older couples, wealthy tourists, or high rollers getting some dinner before beginning their evenings. The service was professional and prompt. We ordered the barbeque shrimp appetizer and perhaps it had been hyped up too much in advance by my family or if the chef had an off night, but we weren't terribly impressed with it. It was good, but where was the "BAM!"? The sauce was mild and somewhat sweet. It wasn't anything to write home about.
I ordered a salad for my entree, the "Delmonico Baby Greens and Tomatoes with Red Onions, Balsamic Vinaigrette, Cheddar Cheese and Sourdough Croutons" salad. This was very good. It wasn't anything to get excited about, but I wasn't really expecting it to be. My husband had the "Charbroiled Dry Aged Beef Sirloin with Bacon Cheddar Twice Baked Potato, Creole Tomato Glaze and Horseradish Cream" that we split. This was really good -- the sauce was sweet & spicy and the potato was wonderful. The sirloin was a little bit on the rare side. He asked for medium well and it was more like medium rare.
We liked Delmonico's, but for the price, I don't know that we would go back.