Stayed there together with my girlfriend for a couple of days in August 2013. First the bad news: The rooms are indeed small and some may nag about that there was no fresh bread for breakfast but single packed buns instead (though they're not really that bad at all). And IMHO this is easily forgotten once you take the good news into account: The staff was very friendly and also went to great lengths to help us with whatever issues we had. This went from simple things as calling taxis and recommending tours or restaurants, to helping us to get our ferry tickets (which was quite a bit of trouble!).
The rooms may be small but they are really lovely decorated, clean and have aircon. Also water pressure was good even on the top floor - some of you may know this can be very annoying in some places. So in short: Very good standard all in all.
The location of the hotel is nearly perfect as it is just a stone's throw from Sultanahmet square and at the same time easy to drive to and from with taxis or busses. The biggest part of all attractions and POIs in Istanbul are conveniently reached on foot.
We had a very good stay, will happily return and therefore can highly reccomend this hotel!