We chose this door grid, as we have a relatively wide staircase, and did not want to make out with spacers. Where Durschgangsbreite still is so totally slim. The installation manual is the ultimate !! We have a couple ever sat on this one door, and we are not inexperienced with regard to build furniture. If you have it done it, that door is really super. By timber it fits nicely into the apartment.
Conclusion: with a revised assembly instructions I would give full marks !!