We can recommend this place for so many reasons. First of all of course: Nik. He's taking care of you and eventhough he is really busy, he will find the time to text you back or to come over for a quick chat. You will receive a message with recommendations for restaurants nearby and things to do and see on Santorini shortly before your arrival. What I highly appreciated was, that one of those restaurants he mentioned was/is the one he's working as a consultant for but he didn't point that out. So I had the feeling that he's not talking you into something. I won't tell you which one because I don't know if he wants me to, just ask him ;-) But you should definitely go there. High quality, everythings fresh and really really tasty.
Perissa is the perfect spot to stay if you don't like it too crowdy. And I mean, the bus stop is right around the corner so you will arrive in Fira in about 10 minutes anyway. The beach is close to Niks place, the water is clean and clear und small colourful fish swim around your feet :) Booking tours in Perissa is also no problem. You will be shuttled from Perissa to the port (or else, depending on the tour you've booked) so living in Perissa won't bring you any disantvantage. Go there, stay there! :)