We had initially planned to visit Machu Picchu for two days: take the train from Cusco an, overnight in Aguas Calientes and head to the site the next morning. However, due to time constraints we decided to book the day trip on Viator. In retrospect I am glad we did:
Even during our short visit, Aguas Calientes left us underwhelmed; very touristy and annoyingly commercial. Second, the time that Viator allowed at the site, was more than enough. We are not archaeologists so the 3.5 hour timeframe gave us the opportunity to walk around and take pictures with great views. I recommend this excursion to people who do not want to spend an entire day and subsequently more money for hotels. I booked other excursions in Peru but the Viator tour stood out as the most organized. The pickup from the hotel was done in a timely fashion. Necessary explanations were provided at the train stations in Cusco and Aguas Calientes. Boarding the buses was done in an orderly fashion. Upon arrival to the site, we were assigned our tour guide. The restaurants where we redeemed our meal vouchers were the best in town.

I recommend Viator for the Machu Picchu excursion. I also, recommend taking the Vistadome train. The breathtaking views are well worth the upgrade