It was a reasonably long tour. We started at the tour office at 6.30am and returned to Salta at 8.30pm. We were the only English speaking customers (the rest speaking Spanish), but Martin our tour guide positioned ourselves at the front next to where he sat so that he could talk directly to us, whilst he used a microphone to give the equivalent information in Spanish to the rest of the bus. His English was very good and he gave lots of useful information.
The trip took a while to get going, but once out of Jujuy the scenery became much more interesting as we climbed in altitude and into the more arid areas.
Purmamarca was a lovely town backed by the multi coloured mountain behind. We only spent 45 minutes here and wished it had been longer. (In fact the tour could spend longer here and reduce time at some later stops)
Tilcara is home to a museum with Inca ruins. This cost an additional 300 pesos per person (for non nationals) and we did not go in (having seen a number of other Inca and pre Inca sights elsewhere), so Martin directed us on a short local walk which gave some nice views.
We then stopped at a local pottery, and (for us) we would have preferred to have cut the time down here (from 45 minutes to 15 minutes ... or even missed it out completely) and spent the extra time at Purmamarca - it's mostly just a shop.
We then drove onto Humahuaca where we stopped for 2 hours and had lunch and a wander. We stopped outside a large and busy tourist restaurant that had been 'pre-booked', but we were free to go elsewhere - which we did - to a nice quiet restaurant. We found Humahuaca to be quaint but rather touristy, and we would rather have spent a little less time here (and more at Purmamarca).
We then returned to Jujuy and Salta with a couple of short stops on the way.
We enjoyed the tour and we thought our guide (Martin) and our driver (Antonio) were very good. The bus was mid-sized with bigger windows and more comfortable seating than a minibuse - we suggest that you check what the transport is before you go.