I spent a weekend at the PH Vienna recently and was quite impressed. The rooms are very nicely appointed (Loewe TV, huge bathrooms). While the interior design was not fully my cup of tea, it was very luxurious and overall practical to operate (window shades, lights, air condition). Given that this hotel is brand-new my room had some teething issues, but those have been resolved by the hotel team very attentively and generously.
The main restaurant is gorgeous, the food nicely done and presented, and staff as attentive as you would expect.
Overall I was very pleased with the my stay. The location of the hotel is very central, about 200 m from Graben, and with it's side entry across the street of "Das schwarze Kameel".