Great place. Beautiful Old City. Lots and lots of great restaurants, places to see, amazing nature. All within the city. No need to rent a car, cheap public transportation and taxi services.
Nothing special, city center is a large place, it is ok for a evening walk.
Sibiu is one of the big cities in Transylvania. The old town is really beautiful, especially in winter when it's covered with snow. Two days would be a good enough time to see all the attractions but it would be good to stay longer and enjoy beautiful Transylvanian city.
Sibiu is a fantastic small city and one of the seven original fortresses of Saxon Transylvania. It's a lively town with a handsome old city with some historic attractions and museums.