Visited Sarmizegetusa Regia and Piatra Rosie in 2016 during a 4-night stay in the Pensiunea Ulpia Traiana in Sarmizegetusa, which - as the name may already indicate, has the Roman ruins bordering its garden (update 2024: now also WHS). The owner of the pensiunea is linked to the Archeology Museum in Sarmizegetusa. He and one of his neighbours drove our 7p. group as private guides in two 4WDs around the area, including up the Orastie mountains with a hike inbetween our vist to the two fortresses.
As I recall it, the views from the mountain at Piatra Rosie (photo) were more impressive than the overgrown ruins themselves, but Sarmizegetusa Regia was a very nice visit. And this way of visiting the fortresses, while having a local guide with us, certainly accounts for one of my stars.
We included visits to Densus church, to the Dinosaur Geopark Hateg (with the Sinpetru formation), and to the Retezat mountains in the programme (all on the tentative list), among many other interesting closeby sites.