Ate here at 10 pm after a long, annoying flight and it was close to perfect and really convenient. (We are staying at the Cosmopolitan, which is where it's located.) Good service. Solid food.
Our waitress was very knowledgable about both the drink menu and dinner menu. Incidentally, the mixologist at this place specializes in gin and tonics. (Score! My fave drink). I started off with a delicious g&t that had mint, cardamom and some lemon in it. The wine menu is pretty extensive, as well, though they only serve Spanish wines....
Since Jaleo serves mostly tapas, we ordered 7 small dishes. The most fabulous of those were the stuffed endives, garlic shrimp and hangar steak. The only plate I didn't care for was some baked shrimp/noodle concoction that had an odd consistency. Overall, the atmosphere is super chill (comfy corner booth situation, dim lights, cool music) and we had a lovely experience. I would try it again.