We just bought this for our 5-yr old for her birthday.  She loves it!  Enjoys the slide the most!  The underneath is super cute too (Velcro is used for the tent).  We got a 9 1/2” twin mattress, fits perfect.  We used Handy to build.  It took 1-person about 3 hours.  He said it was a very easy build and hardest part was doing an inventory to make sure all parts were there.  He also said that it was a nice product, solid wood - no particle boards.