Had four nights at the Radisson Blu Bosphorus in Istanbul last week. No recognition of hubby's gold status, nor of my big birthday as mentioned in the booking - but then none was expected (although it would have been nice!). The original room we were shown was quite small and dark, with the window close to the adjacent building, so we upgraded (for €50 per night) to a larger room with a view of the Bosphorus. Much nicer and worth the extra. Breakfast was included, much to my surprise, and very nice it was too. Without exception, the staff were lovely.
The hotel is in Ortakoy, which was nice enough, but a fair way from the centre of Istanbul. It's supposed to be trendy, couldn't see why though! Traffic between the centre and Ortakoy was pretty dreadful and if you wanted to use public transport, it was bus then tram. The bargain rates more than outweighed this slight inconvenience though.
I hope this doesn't come across as negative, we had a very enjoyable weekend and would be happy to return.