The Lotus Suite was a really excellent base for exploring Istanbul - I would definitely recommend staying there - and Dogan is really nice, responding quickly to any queries we had.
The apartment is beautiful - lovely to have breakfast on the balcony in the mornings or sit there in the evenings. The area is nice, with a few places to eat and a 10 min walk from the river. You'll need a bus to get to the tourist attractions but this is only a 2 min walk away, and buses come regularly. The breakfasts provided were also nice.
Overall I would thoroughly recommend it and would definitely stay there again if I go back to Istanbul. :)