Eight of us went on an early Saturday evening and Okeanos lived up to our expectations based on a friend's recommendation. The food was wonderful, especially the fresh fish and other seafood. The appetizers were also well presented and delicious. Although it is a little pricey for Park Slope it also has the kind of attentive but discreet service one expects more from a Manhattan restaurant. And they do have moderately priced "traditional" Greek dishes if you just want high quality basics.