I was 2 weeks ago in San Pedro de Atacama for a 3 days trip. Winter is a great time to visit the place as it doesn't get too warm during the day.
I booked the travel with Maxim Experience; some trips as part of a group and some in private (to get the most out of the 3 days I was there). I would probably rate them 4 on a 5 scale: correct and responsive as clear plus, but had one day with an old van (driving at only 60km/h to the 5000m top...) which was definitely a minus.
The area is definitely a must-visit place for people that like to be in nature.
Some more info and pics can be found here photodepauw.com/english-home/…
cheers - Pieter