We had a fantastic stay at Eirini's "THEROS boutique house" and would gladly recommend it to other visitors.
We didn't meet Eirini in person during our stay, as she was unavailable (as she had told us in advance) but her friend Luca met us at Naxos port and kindly drove us to the house and showed us around.
Eirini was also available for contact via AirBnB throughout though — responding almost instantly to requests. The only minor niggle we had during our stay was a local water outage one day caused the hot water to run out the next, as its solar heated. Within fifteen minutes of informing Eirini of this, Luca arrived at the house to turn on the back-up mains heating, and we had hot water minutes later.
The house is in a residential area, with room for parking, which was handy for a rental car, and a comfortable 10-15 minutes walk to town. It's sitting on the ring road into the town, so some background traffic noise on the balcony during the day but not overbearing. At night the route home from the town was low lit and a little isolated — this was fine for us, the area felt completely safe, but may be an issue for some people. (That said, there may be a longer more main road back — we took the most direct route — or with a car wouldn't be an issue).
The house itself is exactly as pictured. We had a group of 4 so used the two bedrooms, but it is spacious enough for six people, and not simply to sleep — with big balconies and kitchen, you wouldn't be on top of each other. (The sofas looked like they would be comfortable for sleeping too.)
Eirini/Luca had gone out of their way to make us feel at home by stocking the house *full* of food — two loaves of bread, a dozen eggs, milk, coffee, cheese, ham, cereal, homemade fruit preserves, delicious fresh veg and fruit, homemade biscuits and a bottle of raki! Γεια μας! (Sure, I'm forgetting a load here too — suffice it to say we had some lovely breakfasts and lunches on the balcony).
On top of this, we had every kitchen gadget you could want (milk frother, cafetière, espresso machine, Breville sandwich maker); the house also had a washing machine, which was great for us midway through the trip.
This review is long enough (trying to give all relevant details), but in summary — would happily stay here again or recommend to anyone: great house & hosts, which was one of our highlights of our Cyclades trip.