Functional, clean, but a bit decaying old hotel. Not really the 4* stars worth. Luckily we had a working airconditioning (compared to other reviews) in our room as we we're sleeping there with 3 people and it was over 30c outside. Also no mini-fridge in case you we're expecting that. The bathroom had a bit of a funky smell (part of being an old hotel), but it was clean, not really an issue for me, but people have different expectations from 4* stars hotels.
The area was a bit off putting, very busy street below, so if you are perceptive to noise from traffic, it can be a troublesome factor. So take an extra pair of noise-cancelling ear plugs with you, if that's the case.
The nearby subway station (Steinstraße) was dirty, attracted a lot of homeless people and alcoholics, so be a bit on your toes in the late evenings.
Luckily it's only three stops to the center in Jungfernstieg and in walking distance of Speicherstadt, which displays the old package warehouses reconstructed from the old days of Hamburg. imho the best part of Hamburg.