Look no further. John's apartment is spacious, fully-air-conditioned, well-equiped, secure, clean, and perfectly located in the heart of Athens just a few blocks from Syntagma Square in one direction and Monastraki in the other. The bedrooms are quiet and comfortable; the mattresses and bed linens are great. It was 34-44C/93-110F when we were in Athens volunteering at a refuge camp. Returning to John's elegant apartment with its powerful a/c each night was a godsend. What's more, John and his wife were excellent hosts: thoughtful, kind, and communicative. They welcomed us so warmly and were on hand during our stay for whatever we needed. They also stocked the refrigerator for us with breakfast foods, fresh fruit, cold water, juice, and even a bottle of wine, which lasted us throughout the week. They clearly bend over backwards to make your stay perfect.
In addition to big things like an elevator and a laundry machine, the apartment comes loaded with all sorts of little, important amenities, from extensive toiletries, to a Nespresso machine, to first aid supplies, to listing of local shops and restaurants. Although the front living room with its charming balcony overlooks a lively pedestrian street with several stylish bars that stay open until the wee hours of the night, you do not hear the noise at all in the rest of the apartment. I am an incredibly light sleeper, but I slept so well at John's. The bedrooms are peaceful.
The only issue anyone might have is that the shower is a bit awkward. It is set inside a small tub with two levels in it. It might not be the best for people who are very tall or people with knee problems who have trouble climbing in and out of bathtubs. But the shower itself is good with strong water pressure.
I hope to stay at John's again when I return to Athens; I only I that I'll be able to after the word gets out about how lovely his apartment is!