I stayed at this apartment for a month. The apartment was very recently renovated and the furnishings were very new and tastefully picked. The location is great - it is in the Koukaki neighborhood which is not too touristy and has a great selection of restaurants nearby. The Acropolis and touristy Plaka are only a short walk away. The apartment has an AC in the living room and the bedroom. The kitchen has a coffee machine and basic utensils and spices (no dishwasher sadly) if you want to cook. The bathroom is great and is equipped with a washing machine as well.
The only negative during my stay was the wifi - the apartment was equipped with a hotspot which was underpowered for my day-to-day work. The Upstreet hosting team had some issues getting a proper router installed and working, but were very accommodating and reloaded the hotspot often. Hopefully they have the router sorted out soon and living at this place again would be a no-brainer.