If you exclude the fact that:
It is on the 4th floor without elevator (never mentioned on the description).
It has the narrowest stairway ever, so good luck currying your luggage all the way up.
The bath room and the rest of the studio could be a lot cleaner
The towels are all worn out.
The mattress is probably the worst we have ever slept on, with a huge hole on one side.
One of the windows has no curtain so the sun will wake you up eventually.
Then, depending on its price and its position, not a bad choice to stay in Athens. I would not stay there again though.