The Salkantay Trek was definitely a real experience - we had lots of rain (rain poncho!), hurting calves and freezing nights :-) but nothing worsened the group's spirit and the chef's lovely food put a smile on everyone's face!.
The camping sites were really idyllic and the tents were always ready when we arrived and needed a quick nap. Considering the uphills: They are definitely doable if you are a little sport y - and even if you are not; no one gets left behind and there are always little breaks (pack some snacks).
The only thing that you have to keep in mind are the extra costs for tipping the staff, some transports and two meals that aren't included.
Ps. We even did it without proper hiking boots ;-)!.