Love these things.  I bought 3. 1 easily fits me and a kid and the dog across the top. 
Be aware that they are HUGE.  Make sure you have the space.  
As far as putting them together… holy moly it was some work.  I followed the instructions on the first one and then decided there had to be a better way.  Instead of lying the cover on the floor and trying to cram the back pillow in from the top, I recommend standing the back pillow up and then sliding the cover over it.  Either way, be prepared for a little workout.  It is helpful to have a set of hands to hold the fabric together when trying to zip it up.

I had originally bought these being very excited about being to take the cover off and wash it (because dog) but after stuffing them I’m not sure how often that will happen….. 
The fabric is very durable.  I expect these to have a nice long life. 
The kids love them so much they have been sleeping on them every night for the past week.