I have done only the southern half part of this route and it’s really great. Nice corners and spectacular views. I assume that the northern part is the same cause is marked as a scenic route in my Michelin map.
Great day trip starting from Targu Mures (in diection of Reghin). Until Reghin it's boring and full of trafic, but then it opens and clears up. Road is good, but there are general hazards like oil spills, carriages on the road (and reckless drivers - looking at you drivers from Bucharest). After Toplita it becomes fantastic - incredible scenery, great road. Just after Borzont there's a restaurant (Basa restaurant) which serves great food in a rustic'n'authentic atmosphere.
Between Miercurea Nirajului and Sarateni the tarmac is new (about 1-2 years old), very smooth but there's gravel on the side of the road (and the occasional oil spill) - be careful. Apart from that great view and great corners. The Restaurant at the end (Ciuperca Mica) serves great food!