This is a great hotel. Well staffed and very friendly, smiling staff. The location is about 200 meters from Taksim Square so excellent. We had just arrived by taxi outside when 2-3 people came out. We were travelling with lots of baggage (culmination of the summer in Europe). They took care of it with no hassle - and kept the luggage we didn't need in their storage. The link was quite seamless, including when we checked out and deposited the rest of our bags for them to hold until we got back from one final excursion. The ever-enthusiastic Volkan didn't need a prompt to know we needed our bags. All in all a great experience. Proper 4 star stuff - no cutting corners.
Breakfast was great and well staffed. Hot meat and vegetable options, cold cuts, lots of salads and cheeses - really quite satisfying. Wifi was good too. I was consistently getting 6-12Mb speeds, which is as good as you'll get pretty much anywhere (hotels). It'll easily let you browse and watch youtube or do video chats.
The reasons this hotel doesn't get an outright 10 is because the room windows should be better soundproofed - and the workmanship of fittings, specially the shower door. All perfectly fine and clean - but just looks a bit dated.
I'd go there again without any reservations.
Tips: Master the Taksim Metro Station in the Square. The Metro Line is a great underground link. But take the Funicular to Kabatash and you'll have great overground links to Galata Bridge and Sultanahmet.