Helios is a great great host. Super quick to respond to all communications and super helpful. We were worried about the check in time, since we had very large pieces of luggage and not only he promptly organized a place to store them for us but later ended up speeding up the check in so we did not have to worry about them no more.
The only remark I must do for future guests is, this is a very popular place for nightlife activities. We were aware of that and were actually surprised about how good sound isolation was from all noises coming from the street. But the walls are very thin, so you also have to deal with the neighbors and adjacent bars from the building. There is a curfil at one in the morning (I guess) and everything goes quite. But if you want to hit the bed early it may be a problem.