I don't know whether there was an event on but my visit to Hamburg seemed to coincide with lots of hotels being full or being eye-wateringly expensive. I opted for this one as the most reasonable of what was left, even then I feel it was not great value.
If you can find it, it's a good 10-15 mins walk from the nearest s-bahn station on a busy road, quite a way North of the centre. The building wasn't especially dated as other revues have said, the rooms average and the staff were friendly. As I didn't arrive until 11pm I was very grateful they were still open.