Tennis shoes are not allowed. Fashionable attire is what the dress code is, and no sports jerseys. Jeans are fine as long as you have OK shoes, I would recommend a polo or other collared shirt but I wouldn't go with a striped untucked dress shirt unless you want to perpetuate the Amjack look. I was there twice last week, and was wearing a polo, jeans, and chelsea boots the first time and a solid colored dress shirt, jeans, and ankle boots the second. As far as being the "hottest" nightclub in Vegas, it's the newest for the most part, and it's quite large. There are alot of celebrities since it's new, and it's kinda the flavor of the week at the moment. You'll find that Ghostbar, Mix (to some degree), and the club at the Hard Rock also get a lot of action. I'm not sure about Tryst as I haven't been there, but I heard its good as well.