This trek was very rewarding and well run. The first two days are the most difficult in terms of physical challenge, as you begin at altitude of nearly 4000m and continue to climb to the highest point of the trip, the Salkantay pass at about 4700m.
At elevation the temperatures can get pretty cold at night, but once you descend the temperatures will rise, so it is important to bring layers and prepare for both warm and cold. The last 3 days are not too challenging and more touristy, including hot springs, the tourist town Aguas Calientes and of course Machu Picchu.
Our trip was in late May, but unfortunately we encountered heavy rain on the last day of the trip, and some rain throughout. The only downsides for this trip were that 1. They never picked me up from the airport, 2. with our large group, the van rides between locations were very crowded.