We stayed in a private double room for one night while in Istanbul. We waited too long to book an additional night at our hotel and since the Sultan was close we decided to stay there. On the bright side it is in a great part of town and we actually noticed a very mixed age group of people staying there- not just young party types. The hostel staff was very friendly and helpful. Despite the downstairs being a bar & restaurant it was not noisy in our room. Our room was clean and had a private bath. Breakfast was included. I thought the bed was comfortable enough.
Some things you would want to consider if staying there:
1. In our experience the bar & restaurant staff were not particularly friendly or helpful.
2. Our room was 50 euros! We payed almost half that a block away for a very nice room.
3. Our private bathroom has no separation between shower and toilet & sink area so everything was soaked after a shower.
Perhaps if you are staying there in the dorms it may be a typical dorm experiencing but I think it was a bit expensive for what we got.More