This is just what we needed: a completely modular and interchangeable solution for a small price.  It's on the smaller side, which is perfect for our small space.  Each piece is completely stand-alone, or you can attach everything in a number of ways.  I wish that we could also buy additional pieces, because I'd add a few extra pieces for our family room.  The back pieces are removable with velcro, but the seat pieces are attached.   Very good value.