The Vault is located in the basement of The 9/Metropolitan Hotel. I have visited The 9's other bar this past summer, Azure Rooftop, and didn't have a great experience with bottle service. While I didn't do bottle service at the Vault so the comparison isn't exactly apples to apples, I had a great night in the Vault.
Once you find your way to the Vault (all the way in the back - straight in from the main doors on 9th St - then down) through a bit of a maze, the first thing that wows you, even along the maze, is the decor and the attention to detail of decorating and accenting the space. There really isn't a space left untouched. Every nook and cranny has something awesome whether it be art, a mirror, a couch or some neat light fixture. The Vault really went all out in creating a cozy, mix-use space.
The place was packed when I went there for an event, but the bar was well staffed, and the wait for a drink was really not unreasonable at all. Drink specials for the evening were reasonably priced at $8 (Moscow Mule / Manhattans) and the former were made rather strong.
All in all a great experience. I would definitely like to go back on perhaps a quieter night and enjoy the Vault again. Even though it was busy when I went, I was still able to find an empty bench in a curtained alcove and get out of the main busy areas.