Ioannis' apartment is perfect for a couple- spacious, with a comfy livingroom and a good kitchen. Everything was tidy and clean and we had everything we needed. Ioannis was very nice and helpful with everything we needed.
The neighborhood is awesome- tons of pubs and eateries and within walking distance of central Athens. One disadvantage of this location (not specifically Ioannis' apartment rather than the neighborhood in general) is that it's pretty noisy at nights, but I'd say it still pays off.
Bottom line- highly recommended!