Cons: Small single bed room, just about fit a carry-on case and a backpack. Mattress not fully secured in bed. Bathroom also small, but thankfully clean (which seems to vary from room to room). I stayed on the top floor, more than 140 steps in the stairs unless you rode one of the two elevators (the other broken).
Pros: More than adequate breakfast compared to other reviews. Unless you absolutely crave bacon, scrambled eggs or orange juice in the morning, you'll find different bread, cold cuts, cheese, cereals, yoghurts, eggs, fruit salad, coffee, tea, apple juice, lemon water etc.
Very close to the Hamburg Hauptbahnhof, only across the street.
Could benefit from a renovation, but it would also hike up the prices quite a bit so it is a matter if you look for rather low price and vintage standard, or a very fresh hotel at perhaps 50-70% higher price.