I have the same feelings as Jessica. We, too stayed in Firostefani within walking distance to Fira and we did just that most of the five days we stayed. There are a couple of well done and very interesting museums and several good places to eat, or just to have a drink and chill. We rented a car so also spent some time exploring the rest of the island, visiting a winery, beaches, Akrotiri and Oia. My feelings about Oia reflect Jessica’s. While beautiful, it didn’t feel “real”. That said, I did enjoy our short visit and seeing the iconic white buildings with the blue roofs! I expect whichever you choose will be just right for you. It’s a beautiful island. If it makes a difference, we were then mid October, a perfect time, I thought!