Went with a large group (9) and had a superb dinner from start-to-finish. Service was outstanding throughout. While waiting for our table, the bartender gave us excellent drink recommendations and gave us a few samples - wish I could remember the names of the cocktails we tried, but they were all tasty and well-prepared.
Once seated, our waiter was incredibly attentive and courteous without being overbearing or stuffy, and again offered us some excellent recommendations based on our tastes. They also managed the timing and pace of our meal with aplomb - which I consider impressive for a group of 9.
As for the food, I'll run out of superlatives if I elaborate too much. I had the sweetbreads as an appetizer and the lamb saddle as a main entree. Both were absolutely delicious. Also tried some of the octopus and steak tartare starters - also excellent choices. And bacon bread? Can't go wrong with that.
I've been to a number of overpriced restaurants in Vegas and left underwhelmed - but Sage earned five stars in every regard. I definitely will be returning next time I'm in town.