I have 20" wheels with low profile tires on an Audi A6 S-Line, and the Pirelli's PZero that the car came with offered good road feedback but were getting increasingly hard, uncomfortable and noisy as they started to get older. So when they finally went, I wanted to replace them with something more quiet and comfortable, but also good in the wet and with a decent handling level. The NFera SU1 is exactly the type of tire i was looking for.
Positives: very comfortable, extremely quiet for a 255/35/R20 tire (Nexen says 68dB), good wet grip, great price
Negatives: not so good road feedback and dry braking (compared to the PZero), handling is average
The wear level is nothing special, it wears a bit faster than the PZero, because the SU1 is a softer tire, but not by much. I have done about 12k miles and they seem to be about half their original thread height.