I stayed at Zeynep 3 times, and every time I get exceptional service: knowledgeable staff, very good command of English. All staff are very helpful, I call this a hub because they can help with just about anything from corrective lenses to empty carboard boxes (if I have extra stuff that does not fit my luggage).
Location is superior with tiny old mosque right next door, very quiet and peaceful neighbourhood. 3 minutes to tram station, main means of commuting to elsewhere in this part of town. 5 mnutes from the Cistern, 10 from the Blue Mosque etc.
Under the hotel there is a 12-th century church, it literally frms the foundation of the building. Hotel will be happy to give you a tour. It's fascinating - living in such a historical place.
Recommendations: book in advance and contact the hotel with your specific room requirements.
Cons: just one, the doors between rooms are somewhat leaking sound, but if you are a peaceful sleeper this is not a problem at all.

This is a simple hotel, very well located in the heart of Sultanhamet (the quarter where most sights are). 5 minutes walk to Aghia Sofia, Blue Mosque, Grand Bazar. 10 minutes walk to Eminönü (harbour for the Bosphorus tour). Tram stop (Gülhane) 5 minutes away to go towards Taxim Square.
The owner (Ibrahim) is a well-travelled man and speaks excellent English. He will be pleased to tell you a lot about his city and the places to see (and to avoid). The staff is very helpful: Iulya and Yussef both speak impeccable English and give you good advice.
The twin room we had is quite small and the bathroom is also tiny. Breakfast is simple with tea, coffe, bread, butter and jam, but also fruit and yoghurt.
The beds are very simple and the mattresses not that comfortable.
Price we paid for a twin room was 79 Euros (during New Year's Eve) per night, which I find rather pricey for a city like Istanbul.
Excellent free transfer from airport and back. Very helpful and efficient drivers.

The number one reason for us to come back (hopefully in the near future) to Istanbul (and of course this hotel) will be the superb hospitality from the hotel staff. We will never forget the half day free private tour from the staff to the Asian part of Istanbul. We got to see real places where istanbulites hangout, shop and live.

We are also grateful for all the tips gave by the them for our wonderful sightseeing in Istanbul.

Lastly, of course the hotel condition is good and it's within walking distance to blue mosque, hagia sophia, topkapi palace, other tourist attractions and tram station.

Endran and Louisa
Kuala Lumpur, Malaysia

Everything about this hotel worked well for me--the location is just about perfect, my room was pleasant, the breakfast area has a sweet view and good food, the staff--especially Emre, the hotel manager--was just plain delightful, and (for the first time in my long travel experience) when my cousin arrived and the promised double room was not available, Emre provided a second single room and CHARGED NO MORE FOR THAT ADDITIONAL ROOM THAN THE 10 EUROS EXTRA FOR GOING FROM A SINGLE TO A DOUBLE! Fantastic!