We stayed here from December 22 through the 26th of 2013. It was a fantastic experience. First off, the staff was uniformly friendly and very helpful. The woman who greeted us even brought one of the suitcases up the stairs, even though I could have easily done it myself (and probably more easily than her!). Every time we came back from wherever, the staff would get us any kind of tea or coffee we wanted. There was a ton of fruit free for the taking all day on the front counter.
A number of other guests groused about the steps. They ARE steep, there's no getting around that. However, they are not impossible - ever for smaller people like I and my wife. Plus, it's a mark of being a REAL traditional Amsterdam house. I found them quite interesting. No problems at all.
The breakfast was really stunning too. LOTS of things to choose from. A massive spread of cheese, bread and meats were out there every morning. There was also cereal, yogurt, and fruit. If you take advantage of the breakfast, you can probably skip a meal later!
The bed also felt softer than I usually like... at first. Nevertheless, I slept very soundly and woke with not only no back pain, but the back pain I had come with disappeared. (Back pain after sleeping is something I often have. Not here!)
Finally, I'm not sure what all of the other complaints are about the trams. They are out there. You can hear them if you're looking for it, but it was nothing that would wake me up. Maybe this was just us. I grew up in suburban Detroit where nighttime gunfire is fairly common and I live in Japan now where people are packed in pretty tight most places. If you have problem with (mild) noise, Alp Hotel gives you some free earplugs. We didn't need them at all.
I'd stay here again in a heartbeat!