Konstantinos' place is fine.
Located at a great point in the city centre. It has all the basics you will need.
The balcony was a bit dissapointing because it was very small and not suitable for 4 persons.
Also the building is a bit old (as are all the buildings in Thessaloniki city centre) so try not to be too loud in the evening or you might end up annoying the downstairs neighbour as we unfortunatelly did at first.
Overall I recomend it.