I was at the hotel this past weekend and while there was a bit of a problem with the thermostat in my GC room, I enjoyed the food and drink in the lounge and a Bosporus view not blocked by the Ritz Carlton, and had a very pleasant stay.
What is a problem is not the hotel's fault - there is construction all around Taksim Square, and I found myself walking in muddy roads on several streets without sidewalks, or broken pavement. If you only take taxis or cars to and from the hotel it is no problem, but if you are a walker like me it is quite confusing to get around - and this applies to all of the hotels around Taksim Square including GH, IC, Nippon, Point, Taksim Suites, etc. Cumhurriyet St. is gone.