This is my second time staying in the apartment, and I can recommend it unreservedly.
The apartment itself is very comfy, nicely decorated and has everything you need for a comfortable multi-day stay. The location is perfect, with the lovely Dexameni square at your doorstep, great cafes, bars, and restaurants within a couple minute walk, nature trails in mount Lycabettus only five minutes away, and the town centre within walking distance too.
Last but not least, the Upstreet team who manage the property are a great group of people. Very easy to communicate with, attentive to detail, and highly responsive to guest enquiries.
Highly recommended place and hosts, I would stay there again without hesitation.