The rooms are basic, but my room was clean and quiet. The staff was friendly. There were problems with check-in though. Our friends were told that they would receive a text when their room was ready. No text ever came. When they finally got a room it was dirty. The hotel's solution was to downgrade their room. They eventually straightened it all out, but it was an unnecessary annoyance.
My companion and I decided to go to the Pool at Mandalay Bay since the Monte Carlo's pool is being renovated. No one at Mandalay Bay could direct us to the free shuttle which was supposed to bring us back to the Monet Carlo. Concierge at Mandalay Bay said that the staff at The Monte Carlo did a poor job of providing them with such information. It took us over a hour to catch the shuttle back to the Monte Carlo. SO BE WARNED: THERE IS NO POOL AT THE MONTE CARLO UNTIL 2018. It was a very long walk to get to the pool at the MGM Grand too.