We stayed at the Sheraton in Lima for two nights during our mileage run. The hotel is an extremely noisy section of town. There is also a tremendous amount of auto and truck exhaust. I'd recommend staying at other hotels in Lima. While we were in Lima they were constructing the Marriott which overlooks the ocean. The hotel looked beautiful.
If you are going to stay at the Sheraton it's worth the extra money to stay in an upper room.