A K.
Yelp
I had a late lunch during a very quiet time, so I have no idea how the service holds up on a busy Friday night or anything - but I had a lovely meal.
The Duckstein was well-poured, the rösti was crispy and not greasy, the portion of ham accompanying it was generous, the mushroom-cream sauce pleasant, and the Tirolean apple streudel I had for dessert was superb (warm, flaky, judiciously spiced, served with ice cream, thick whipped cream, and a few raw apple and orange slices).
I'd give it five stars if the menu were more inventive and/or the prices lower, but for a little slice of Hamburger cuisine on a street it's a real pleasure to walk down (the pedestrian-only Colonnaden), you could do a great deal worse!