This apartment definitely lived up to the great reviews we had read prior to booking. The views from the balcony were amazing! We woke up every morning to watch the sunrise. It was convenient being in between the two main cities of Fira and Oia. Fira was especially close, and we liked to use the caldera trail to get there. We loved visiting the market right up the street to get items for picnics and breakfast. Their staff were so friendly! The bus stop was a 7 or 8 minute walk away.
There was always someone available at reception during the day, similar to a hotel. They offered suggestions and helped book activities (we did an ATV rental with them). The place was so clean! They do a great job of keeping the grounds and apartments in good shape.
We found an amazing spot to watch the sunset on the nights we didn't feel like going far from home. There's a church across the street. Walk along the church on the caldera trail as if you were going to Oia (aka north). Take the white steps that are on the backside of the church up and you'll see a rocky cliff type thing jutting out. You can walk out there, and it's a PERFECT view free of other people! And it's big and flat, so completely safe. We brought picnics and a tripod to do a time lapse of the sunset. (Sorry that was so detailed - but you should definitely give it a try. The second night we had people noticing us from the trail and joining us because it was so perfect).
Anyway, there were only a couple minor "cons." The shower/bathroom are small so it was hard not to get water everywhere. Maybe some firmer shower curtains would help? And we'd arrived at the Airbnb by bus (it was only a couple euro per person). Our return flight was very early, so we used the airport shuttle provided by the Airbnb. The 30 euro fee was pretty steep for a 10 or so minute ride to the airport. A great service, just a little pricey for what it was. And maybe the ride would be longer during the day with more traffic?
Anyway, we highly recommend this place and Santorini in general! Definitely book it and start planning!