I've now owned these a couple of weeks.
The comfort is very good and the small quality of life features are great, i.e. earpads that work with glasses, the little bit of cable coil right before the plug into the cup which eliminates cable microphonics, the clicks and marking for the headband extension, allowing repeatable adjustments before putting on the headphones, and the large L/R indicators in the cups.
The design and build is Sennheiser at its best: simple shapes, simple mechanics, low number of constituent parts, low weight, and likely very durable.
Sound is very useable out of the box. Nothing that sounds off, though they are clearly not completely neutral for me. I've added some EQ based on measurements (I can't for the life of me work with sine sweeps) and spent several evenings listening to classical music on them without feeling the need to grab my normal go-tos for that (Dan Clark Audio E3, HD800 with EQ).
So all in all an extremely well-rounded headphone, well worth the asking price.