After a few visits at The Union Bar, I am afraid that my review of the place is very clear: This is…read morenot a venue to waste your time at! There are many good cocktail bars in the city. Quite a few has chosen the appearance of 'speakeasy', where you need to know where to knock to gain entrance. The Union was one of the first to adopt this trend, it seems their early success has really corrupted the place, its drinks and service level.
There is often a crowd at the union. From what I can tell, it's mostly from the continuous crowd of know-nothing tourists that keep circling the place, fueled from old reviews in Lonely Planet.
Don't let this mislead you! The union is basically a scam. You get overpriced, really poorly mixed creepy cocktails, at a serious price premium compared to almost anywhere else in the city.
My only advice: DON'T GO THERE. Rather check out anywhere at Gammel Strand, Congo, Umami or Nørrebro/Vesterbro. The Union Bar just sucks, don't be misled.