So to start off, the room is VERY small (much smaller than you think). And reaching the room is super fun too, you'll have to walk through a hallway full of trash all over the floor. Not a pleasant start, huh? But it doesn't end here. The towels provided had stains all over them, so good luck if you want to shower after a long walk through Istanbul. Oh and if you're thinking to sleep in the morning, forget about it, the building has non-stop renovations going on.
Location is not the best either. You'll have to climb an upward hill to reach the main street. If you like extreme cardio, great, but for most people this is just absurd.
The ONLY good thing about it is that it has a working elevator, which deserves at least a few stars.
But overall, the whole experience felt very unpleasant and I would NOT recommend it to anyone quite honestly.
For the same price, you can stay at a 4-star hotel in Istanbul.