There's a reason most of it looks like airport furniture:
KE-ZU specialises in the sales, marketing and distribution of high quality contract furniture throughout Australia.
1 doesn't have enough height to offer support, and I don't care for the style - the legs especially. Visually if you draped it it would be acceptable, though it would still appear uncomfortable
2 looks comfy, and would be sweet in leather, but I have a futon with a similar profile and it's bad on the back after a awhile. Also, it needs armrests. With cushy armrests, it could be very livable.
3 is totally impractical and uncomfortable, though the magnetic clasps are an updated feature to this style that might prove functional. If whimsy is the purpose, giant foam lego pieces might be as suitable. Fine for the kids playroom.
I still don't like the legs on 4 and 5, and now there's even more area without an armrest.
I don't know how you sit, but I have found that the most comfortable seating comes from improperly using a chair or a sofa so that the armrest becomes your backrest. A situation where a sofa has three or four people asscheek to asscheek while facing forward is rare, and a coffee table cum ottoman is required for comfort.
this is passably styled and looks like it has the potential of being comfortable, though it would be highly dependent on the materials used.
It all seems to be furniture that says "Sit on me for 20 minutes and I will let you rest your feet, but don't even think about curling up with a book"