We had a wonderful 4 night stay in Vrachia aprtments. We had the apartment closest to the pool and a beautiful view of the sea right when we woke up. The reception was very responsive and helpful to any of our needs. There is breakfast provided with all your morning needs (coffee, OJ, yogurt, apples, bread). If you just need a quick filling before a long day in Oia, this does the trick. The AC was excellent, and the pool was lovely after a long day in Oia.
I wanted to offer some advice and positive feedback on location. While Vrachia is not directly in Oia, it's about a ten minute car ride on the North side of the island. It's nice and quiet with steps leading right to the beach. If you plan to stay at the apartment most of the day, I'd recommend getting water shoes for the stony beach. We opted to often take the bus since we could not rent a car (we didn't have our international driving permit), but the bus stop is not convenient. It's a ten minute walk down a road with limited walking space and crazy drivers (also very hot). Once you get to the bus, it's only 1.80 euro one way, but you may have to wait in the heat. The bus is also very crowded and you will likely be standing. The good news is that there is a brand new beach bar right at the bus stop, so you can get there early enough for a drink while you wait for the bus to arrive. I would not recommend using the cab service. It's 25-30 euro each way for a short drive. The cab service is not reliable and will try and rip you off, so be aware. Just 5-10 minutes up the street from the bus stop is a winery called Domaine Sigalas. It is definitely worth the walk (just bring an extra shirt), putting it at about a 20 minute walk from Vrachia.
Other than the small inconvenience of the bus stop, our stay was amazing. You don't get the beautiful views that Oia has to offer, but you can easily make your way downtown for those experiences. It was very refreshing to have some peace and quiet from the busy town. The Vrachia is definitely worth the value. We made great memories here and would recommend it to everyone.