Great experience on this gorgeous island! Gasparis was a great host and the apartment was beautiful and very clean. He provided us with water and wine in the mini fridge, picked us up and dropped us off at the airport for cheaper than a cab, helped us book a tour to the volcano and hot springs, and even gave us a little souvenir when we left! Everybody we met was very friendly.
The apartment is in Perivolos, a 2 min walk from the beach, which is much less touristy than Thira, Oia, etc. We almost always had the beautiful black beach to ourselves, but there were still a good amount of restaurants and bars near us for a more lively atmosphere.
It was a 30 min walk from the bus stop, and the buses stopped running at around 11. If you want to get to many different places on the island by bus, you need to take into account the walk to the bus station and the fact that all buses leave out of Thira only, so you'll have to take a bus to Thira then out to another location on the island. If you're trying to get somewhere quickly or trying to get back late at night, you'll have to take a cab (usually around 25-40 euros for our group of 3). It was not difficult to figure out at all, though.
Overall, a great experience! We had such a great time in Santorini and would definitely recommend this Airbnb.