Lovely hotel and the owner, Julia, was wonderful - welcoming and always ready to help. The young man at the desk in the evenings was nowhere near as pleasant, sadly, and we struggled to get useful local info from him on the crucial first night when we, as two women, were trying to orient ourselves. He was completely uninterested, which is a real shame as all the other staff (including the lovely breakfast cook) are so friendly and kind.
The rooms are small but perfectly fine, esp if you don't have much luggage. No lift but it's a small hotel of maybe around 15 rooms. Be sure to turn left out of the hotel to get to the restaurants and tourist areas. The area you have to pass through to the right is poorly lit and less pleasant - the route the young man told us to take :/
And again, contrary to what he said, it's perfectly easy to find vegetarian food locally.
Overall, we thoroughly enjoyed our stay in Istanbul and would happily recommend 9 Doors - the hotel just needs to ditch the rude and unhelpful young man (wish I had noted his name)!