My stay was in room 107. The pool is nice, the view is great, and the location too, but those are probably the only positive points.
We were on vacation so to avoid unnecessary conflict during our stay, we did not give too much feedback to the hotel. The room is small and narrow. The light in the living room needs work especially in the area where closet is.
The bathroom needs updating. The bathroom is also very small. Rust is on the mirror stand and the shower head holder is about to break (luckily there is a rain shower head). The bathroom flusher mounted on the wall if it wasn't pushed back to the right position, the water will not stop. The flusher is plastic and the plastic mechanism could of easily broke during our stay, but lucky it did not. The water faucet to the sink in the bathroom cannot be turned up to normal water flow because there is barely any cold water to balance the temperature.
The bedroom on the 2nd floor is just the bed and we cannot walk around it. The climb is very steep up and down like a ladder positioned 80 degrees.
It wasn't all bad because Petros is friendly. We still had a good time in Santorini, but to be honest, among the other hotel my friend's stayed, Kallisto Hotel is the most expensive but had the worst room amenities and rooms looked the oldest.
I am not sure what the other room numbers are like, but maybe 107 should be off the market.