We had a great time on the Inka trail with Inti Sun Trek. Jesus was great throughout the planning process, helping us to arrange the trek and working with us fit in our visits some other parts of the sacred valley afterward, and our guide on the Trek was great, taking his time to hang back with the slower members of our group and helping us to take the time to enjoy the experience. If you're going to visit Machu Picchu you should really do the Trek, while Machu Picchu is cool on its own there is so much more you get to see by doing the trek, the scenery is amazing, you camp out in incredible places, and the food is great.
One of the great things about Inti Sun Trek is that they keep the groups small. We were on the trail with some huge groups of 16-22 people which I'm sure is fine way to do it, but if you want the experience of traveling with a smaller group this is the way to go. There were only 5 in our group which really made for a more enjoyable trek. The equipment is also almost new and very high quality - the sleeping bags especially I was concerned about renting but they turned out to be very nice. The porters and the cook were also great and we had some amazing meals including a cake which I'm still trying to figure out how they cooked in a tent, on our final night.