Steve's place is just wonderful.
First of all, it's Kolonaki. I've lived here for 40 days back in 2017, but I was much closer to Lycabettus. I wouldn't recommend that: even though living up high looks nice, it takes a lot of energy to get home, especially if you're with groceries. Steve's place is right next to the Kolonaki square. It's around 8-10 minutes walk to the Syntagma square (the center of Athens), there are 3 grocery stores very close: OK, Kretikos and Sklavenitis, and there are plenty of restaurants, shops, cafes, and bars just a few minutes away. Kolonaki is the safest area in Athens, it's probably one of the most expensive too, but there are many reasons to pay for it more. Once you live here for a bit, you won't choose any other area.
How about the place itself? It's good. It's clean, it looks modern, the internet is quick enough even for me (I come from Lithuania, so you can trust me on the Internet speeds). It has a fridge, shower, cooking stove, coffee machine, washing machine, iron, hairdryer, TV, pretty much everything you might need even for a long stay.
And it simply looks nice. Mostly black & white, minimalist style. The way I like it. All in all, it's a 10/10 apartment, and Steve's communication is exceptional too, you won't have any problems. If you're looking for the best experience for a moderate price, this is your best bet.