The only reason for not giving five stars is that the overall décor is a bit 'tired' and it could all do with a bit of redecoration and upgrading. No major complaints, just that it is showing its age (I guess built in the 1970s and the main concourse is very much of that era).
A MAJOR plus, maybe even warranting the fifth star, is that they provided a free bottle of water and made clear that the tap water was potable. We found bottled water outrageously expensive in Argentina, often in hotels 45 times the price I would pay for Evian in Tesco in England. There's free WiFi (unlike some vile places in England that like to charge, we found free WiFi in hotels in Argentina and in the airports).
Our flight onwards from Salta was cancelled by Arolineas Argentinas, apparently a common occurrence, and the Sheraton re-accommodated our group with no fuss.
The hotel is on an escarpment above the town and so a shortish walk to the town, it is downhill there and a significant uphill walk back, though we found taxis fairly plentiful and not expensive.
We found the bar/restaurant on the ground floor fine, decent food and good enough value for money. The wine was no more than in town restaurants, and less than some. It's a bit of a 'quick food' setup and there is another more formal restaurant. Breakfasts seem identical every hotel in Argentina - perfectly adequate but not in any way distinguished. 'Hot' food restricted to scrambled eggs and bacon, often rather tepid, but as I say this is the same everywhere.
Money changing we found an issue in Argentina generally, and although they have a casino they would not change USD. There are ATMs in town, but like everywhere we found, limited to ARS 2000 (about £100) and a charge locally of about £5 (plus whatever your English bank charges).
Staff were helpful and efficient.
I have no hesitation in recommending this place for a few nights. Salta is a nice place and a nice base for Northern Argentina.