So everyone knows about the W. They are the hippest of hotel chains around. Their Scottsdale location is no exception. They cater to hip 30s/40s crowd for sure and it's definitely a see/be seen type of place.
They open up the bar area by the pool and have bottle service at tables nearby. Also there is another bar right as you come up the stairs. The vibe is very clubesque and everyone is dressed sexy as hell. This is the place to go on a Saturday night when it's nice and warm out and you want that cool in crowd/DJ kind of night.
You either have to know someone staying at the hotel and have a key or likely will have to pay a cover and/or wait in line. Just like any other club. I'd say it's worth it if you are looking for a good time.