We stayed at the Atlantida Villas for several nights in the middle of September 2010.
Our balcony view was amazing. Absolutely stunning - and we could see the sunset from the side of our villa's balcony easily (some people have said there is no sunset view?). Just a memo - Caldera view doesnt mean sunset view - the sun set from Oia's furthest point. But I would take Caldera view over sunset view any day anyway, because you can always walk down and see the sunset.
Anyway! The service at Atlantida was great too - we were even provided with a whole room, free of charge, at the end of our last day to shower/change after the beach before our flight - really above and beyond service, which was fantastic.
The problem with Atlantida is that, I feel they know they can get guests regardless of their accommodations, because they have such an unbelievable view of the caldera from their rooms. The rooms were really, really tired - furnishings were hastily "renovated" with fresh coats of paint - the bathrooms are old, the beds are pretty hard (but not so uncomfortable you cant sleep, mind you)..... I understand that full renovations takes a lot of money - but would getting a handyman to fix small but really irritating things, like our shower head that had no holding mechanism on the wall, meaning you had to hold the shower head up while you showered, or the door locks that were really old and jammed constantly - be so expensive? Probably not, and truly, for the price you pay I would at least expect a shower head that sits on the wall!
If you want a caldera view Atlantida Villas is probably a good choice considering we couldnt find a place to stay that had caldera view and wasn't a zillion dollars a night - mainly because most of the others are right in the village of Oia (Atlantida sits a bit outside, but not too far - walking distance for sure, and we hired ATV's during our stay which made it easy). But if we return we will be opting for a hotel without caldera view, considering you can see the caldera constantly from Oia, and practically any restaurant there!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC