We stayed at Dosso Dossi hotel for 4 nights on our recent visit to Istanbul and it was very good. Here's a comprehensive review of the hotel.
The good(s):
1) We booked an executive room and was provided one on the first floor. It was spacious and had everything we needed. The bathroom was clean and has other amenities.
2) The location was central within close proximity of Hagia Sophia. Plenty of travel options whether it is by foot, tram or taxi.
3) Breakfast was brilliant and we had a very filling and satisfactory breakfast every day. There were plenty of options with a English and Turkish spread and loads of desserts, puddings and fruits.
4) Staff really go an extra mile. Kudos to the reception team and concierge (apologies didn't note down the names) who were very good and helped with our queries everytime. We also loved the work done by the guy who painted our names in the ottoman style outside breakfast lounge.
Can be better:
1) The carpets were really dirty, don't know whether this was due to the weather but they looked very worn and patchy.
2) It was very noisy in the morning. The walls must be thin and as we were close to the stairs, reception and above the kitchen, it got noisy after 6am every day. Road noises weren't that bad despite being on the 1st floor facing off to the streets below.
3) The gym was very well equipped but a bit too congested due to smaller size.
Overall a very good hotel, gets a solid 4 star. Highly recommended if you're looking for a hotel,