Location: Fantastic. Downhill from lots of great cafes and bakeries, near Karaköy (really lively and hip area), very cozy and safe place.
Security: Great, doors have lots of bolts and you need a password or tag to enter, cctv is there, really solid.
Host: Best thing about this place. He went out of his way to help in any way he could, even in things that were out of the ordinary and exceptional.
Overall: Worth the visit if you want a cozy, safe stay in a quiet location with a host who will help in whatever way he can.