By far my favorite hotel in Istanbul. The location is great, I can walk up to Taksim (?) Square and do a bit of shopping, eating and people watching. The staff is by far the best I have ever had the pleasure of dealing with; and is the main reason I keep coming by to this hotel when I can.
Yes, the rooms could be a little more hip and modern, but they are nice and classic as you would expect from the Rtiz name. If you pay a little more and get concierge access/club lounge its well worth the extra money as the drinks in the lounge are free and the food is good.
If you are looking for a place to be feel like you are a king ... then this is it. The spa is also very good, and I have been known to spend more money on treatments than my room!