All i will say for now is that it's lovely. A little over an hour by ferry from Kadiköy lies a different world. There are no taxis. In the Adalar municipality - the Prince's Islands - there are no cars, in fact, save a few trucks owned by the municipality. Instead, the streets are crowded with bicycles and horse-drawn carriages. Hand carts are common, and a bakery delivery man pedals a bicycle with a load of loaves drawn behind it. Another workman, just finished loading a wagon with bottled water, clucks to the horse and sets off. There are thirsty tourists to serve, and here on Büyükada, the supply chain makes use of timeless machinery.
The "big island" pier is crowded, and the stream of people thins as one leave the streets around it. On a rented bicycle (lines for the carriage rides are rather long) you can see a lot more. In back streets, gardens are everywhere, though only wisteria, acacia, and a few roses are blooming yet.
If you go to Büyükada, friends tell me, you should hike to the island's peak and visit Aya Yorghi Church and Monastery, from whence there is a spectacular view. Alas, my traveling companion had sore feet, and a slipping bicycle chain, so we didn't make it far.