I had an excellent stay at Nikitas. The patio was the highlight, and a very relaxing place to hang out and look over the city. A bit out of the centre, but could taxi/metro anywhere easily. And restaurants/amenities close to the apartment were fantastic. I had a great sleep: the bed was very comfortable and no noises from neighbours whatsoever.
The only cons were the wifi - slow and spotty, so if you're looking to work in the apartment, this is probably not a great choice for you. And, the hot water runs out very quickly if you want to shower.