zum Kuckuck in Vienna
No, I always pass this small place. It seems to be catering to the 60+ crowd, being small, "gemütlich" and very old-fashioned. The recently published Falstaff Guide gives 80 from 100 points and mentions some improvements since last year.
So, if you are looking for a small, cozy and old-fashioned place offering classic Viennese cuisine, you might find it is a real "trouvé".