One of the best apartments I've been to all around the world! Huge, sunny, spacious well-designed loft space with perfect zoning - dedicated bedroom (can be made more private with a thick curtain), kitchen with a small table and huge dining table, several extremely comfortable sofas for chilling out and basking in sunlight coming from windows looking out on the surrounding rooftops on 3 sides. Having a private sauna is huge - even if it's summer, warming up your bones after a long day of adventures is such a joy. And don't forget the plants all around the house, so well designed to have this natural touch. It's wonderful to have all this space for a couple, as it's an open space it also may work for a family with kids staying on a sofa.
The apartment is in a great location, you have very convenient connections to Istanbul's public transport system (which you will use as traffic is hideous and taxi drivers are not customer oriented) - 2min walk to metro, 2min walk to old-school underground funicular getting you down the hill to ferries sailing to Asian part of the city and tram leading to Old Constantinople with Hagia Sofia, Grand Bazaar etc. There is a touristy Istiklal street just around the corner - it's up to you how to use it, just get fast food and Starbucks or fully immerse into its craziness. One bad thing about it is clubby music noise on weekends - it is really loud, beware if you're a light sleeper.
Özra is a kind, welcoming host which will get you out of any trouble (although you won't have any). She was very helpful on each stage of our stay. We really hope she will host us again if we're back in the city and it will be a pleasure to communicate with her again!