All good things were already mentioned by other reviewers.
Here is our little anecdote. We send our request to stay very late (even forgetting about the change of time zone) as we just arrived in Greece. Within minutes John replied. When we arrived, we had trouble with the address (our mistake). John was extremely patient with us and accommodating and he even picked us up. Thank you very much, we’d definitely be staying here again.
The walk to the upper town Ano Polis takes only 10 minutes. We like to walk and went all the way to the promenade. It’s a bit of a distance (~30 minutes) but if you are good on foot, it’s a great way to explore Thessaloniki.