Okay, so Uniun is a club in the "King Street" hood, meaning you cannot escape the King St bros. But to be honest, this club is probably as fun as it gets in the area. If you like dance music/the DJ genre, and flashing lights - this club is for you. It's also quite spacious with a downstairs area for chilling, and an upstairs area for dancing your butt off.
This place loses a star for being insanely packed for big-name DJs. To the point where you cannot move. This also affects the line outside. It's always huge and takes forever to get in the door. They oversell their events big time. The last time we tried to go there was for Nicky Romero. Bought our tickets well in advance and the lineup for ticket holders was approximately 2 hours. As it was sold out, we just sold our tickets to some people on the street for what we paid, hopped back in a cab, and peaced.
My suggestion is to go here for a DJ you like, but perhaps not if they're a huge name. Save your money!