The view at night is breathtaking. That is all what you go for, donot expect a fancy cocktail coming up. The cocktails were expensive 370baht and not at all fancy or tasty. Just mixed and put in a glass. The atmosphere was nothing awesome. The bar was crowded and so we were offered seating in restaurant. There were few people dressed really classy, but didn't know that smart casuals also allowed collarless t-shirts.
Just go for view and nice breeze. Also one tip for photographers, I was objected by a stewardess for using tripod. You might want to check first.