Took about 3 hours to complete assembly by one person.  Everything was nicely packaged and clearly labelled, which was a user friendly touch that saved me time.  For those who had issues with the hydraulic not closing, I had the same thought after putting the component in.  Then I realized I needed to sit on the edge to put sufficient pressure for it to actually go down.  When I put enough weight on the frame (simulating the weight close to a mattress) the mechanism closed as expected.