Within the price range this is certainly one of the worst hotels you can find in Hamburg, at least in terms of customer service. While the rooms are nice, the staff is untrained and in no way service minded. The restaurant serves incredibly overpriced food that is sub-mediocre at best.
My partner and I had a very unpleasant experience at this hotel, involving the service of both the restaurant and reception as well as retroactively being incorrectly charged for having taken items from the minibar, although the hotel later admitted that this was a mistake and the charge was reimbursed.
We wrote an email with feedback on these events and our experience of the stay to the guest relation manager who didn't even grace us with a reply.
There are many excellent hotels in Hamburg. This is certainly not one of them and you will be best of choosing another option.