Visited Santorini in the off-season so a lot of things were closed. That said, 3 Daughters ended up being really close to the main thoroughfare in Fira and getting great food, coffee, and even a SIM card for our phones wasn't more than a 2 minute walk away.
Since it was less busy, we rented a car and had no problems parking nearby and even getting around the island from this place. Made a big difference.
I wouldn't expect to cook here but having a place to keep some meats, cheeses, and yogurt was more than enough with all the great options for food on the island. It even meant having a bottle of Santorini white around!
The place was great in the off-season, I can only image it getting better with nicer weather and more things open.
We both love to walk and explore so this was great. If you want to just walk out your balcony and relax going for one of the cave suites may suite you better. However if you don't mind getting your shoes dirty it would be hard to go wrong with 3 Daughters.