It was hard to find this company on TripAdvisor since TTG uses several URLs, like privatetoursinistanbul.com and touroperatorinstanbul.com (which we used).
We chose this agency after asking for 10-day tour itineraries and prices from them and one other agency after dismissing several others based on reviews, their sites, and their prices. In booking, we found that the itineraries were smarter and more compact than the competitor. For example, TTG would give us a flight in the morning and a tour later in the day, whereas for example the competitor would schedule a "free day" with a flight in the middle of it.
It seems most Turkish tours are arranged between numerous guides, drivers, and subcontractors, especially if you are visiting multiple regions (We visited Cappadocia, Istanbul, and Kusadasi). We never had the same guide twice, but TTG managed these transitions so perfectly that we were never concerned. All of our guides were the highest quality, friendly and informative. Our group sizes were always smaller than others. We would often see two or three tour buses full of people pull into an attraction, and be very happy that we were in a small group of just 4 to 6 people.
TTG is very flexible in arranging tours around everything you want to see, when you want to see it. The tour itineraries on their site are just suggestions that you can customize the heck out of, adding "free days" if you'd like.
I can't say enough good things about TTG. By the way, our warm, friendly representative was Ozlem, and she was always available for us.
If you own or manage Private Tours in Istanbul, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.