My husband wanted to go to a Steakhouse (capital S intended) for his birthday, so after detailed consultation of past posts on this board and scrutiny of the menus of KO Prime and Grill 23 & Bar, we went to KO Prime, and turned out to be, on the whole, very satisfied.
What was truly great about it was the steak. He had the New York Strip with Maldon sea salt, and it was, he said, the best steak of his life. It was incredibly beefy-flavorful and tender, and, like my skirt steak with blue cheese, was utterly perfectly cooked--every millimeter, down to the skinny tail end of the steak, was exactly medium-rare.
The service was also good, in that they responded to my OpenTable "special instruction" note that it was a birthday by giving us a great table (with a view of the Old Granary Burying Ground), and birthday-ified the dessert we chose (candle, "Happy Birthday" in chocolate on the plate) without being reminded. However, the servers were also too attentive with trying to take away plates, especially between the app. and main, so that we ended up feeling rushed. The room was by no means packed at any point, so I don't think they were trying to turn our table; it was just their style.
The atmosphere was pretty good. The bar was hopping when we got there (7:30), but the dining room was pleasantly quiet. The colors and fabrics are rich and subdued, kind of metrosexual rather than steak-house masculine, which I mean as a compliment. I wish the background music hadn't been techno--I wanted relaxation, not energy-energy, but oh well.
The "ceviche-style shrimp cocktail" app was okay but was perhaps too cold--the shrimp, rather than being tender, were so firm they were almost crunchy. The plantain chips that came with it were very salty and very good. Our sides, Brussels sprouts with bacon and frites with ricotta salata and rosemary, were both very good. Dessert, a frozen mint mousse with a molten chocolate center, was yummy, like a haute version of Baskin-Robbins mint chocolate chip. The texture of the mousse was a tiny bit icy, but the flavor was great.
Also, important to note: the menu is significantly reduced from what is shown on their website--there are about a third fewer cocktails and sides, and some reductions have been made in the mains and apps. The entire "Mushrooms" section of the sides menu on the website, featuring various exotic mushrooms available a la carte, has been cut and replaced by a single side dish called "mixed mushrooms," and the "Charcuterie and Offal" section has been slashed--no more brains or tripe. None of the steaks on the actual menu advertise themselves as being dry-aged, although the NY Strip tasted aged, as the website says it is.
So, KO Prime turned out to be somewhat less interesting than I expected, but we came in large part for the steak, and in that we were absolutely not disappointed. Aside from the steak, the food was not mind-blowing but satisfying. I chose it hoping for a more date-y atmosphere than Grill 23, and I think that was also a good call. And! We had an app, two steaks (one in the $40 range), two sides, a dessert, a cocktail, and a glass of wine, and I was bracing myself for the check, but it was only $147 (including tax). So that was satisfying too.