I have checked out almost all the rooftop bars in NYC and this was the last on my list. I have read/heard countless stories of the staff attitude but I saw none such behavior on my visit. I was admitted almost instantly with no issue. When the rest of my party showed up, again, no issue.
The lounge is split in two - outdoor pool area and indoor bar area (both are fairly small but intimate). During the summer, the outdoor pool area is the place to be. Almost everyone is in bathing suits (seems like anyone can hop in, not just hotel guests). Getting a seat here is nearly impossible on a nice day so be on the look out when people get cold and vacate the pool and benches.
Fortunately, I lucked out on this day. It happened to be the same weekend as the Puerto Rican Day Festival and the DJ played a good salsa set. Salsa dancing on a warm summer day on a rooftop bar in Tribeca? Priceless. The DJ continued to play some great music spanning many genres of music (raggae, Latin house, dance etc.)
The drinks are expensive $15-$25 (more expensive than most rooftop bars in NYC but the views are amazing). Given the height and location, you have some incredible views of the bridge, skyline, Freedom Tower, water (I would say about a 300 degree view).
Sunday funday is great here and I will definitely be back on a hot day. Sunsets are amazing here so plan accordingly.