Thank you all so much for your feedback. I have decided to send them to Mesa Grill. Hopefully they will enjoy it.

My boss and her husband will be in Vegas later this month. They want the best food in Vegas - no need to worry about the cost. They are booked to eat at Guy Savoy and Joel Robuchon at the Mansion for their dinners. I had made reservations for lunch at Bartolotta, but they have stopped serving lunch and cancelled the reservation! I have seen quite a bit of talk about Mon Ami Gabi and Commanders Palace for lunch, but would appreciate comments regarding which has the best food. Or perhaps there is somewhere else that might be more appropriate for them. They want really top quality food.
Thanks in advance.