Katia's place is very cozy. A small appartment that is perfect for two people. Bonus points for a very good coffee machine in the kitchen. The location is also very good, close to metro station and in the middle of a lot of good and affordable restaurants. We especially recommend Chez Funda, a vegetarian Turkish Mezze restaurant nearby.
Please note that the appartments are not very well isolated (because of their age), so you will hear some noises from neighbours, which didn't bother us.