The great thing about the Sebo design is that the bag doesn't cover the pre-motor filter, so the motor's not having to pull air down through the bag. The filter is at the side, so the suction stays 'stronger for longer.' When you empty the bag, it's solid like a brick, packed right to the top. When you put a new one in, it's amazing how much lighter the cleaner feels!
Just so we understand where we are now, Model2, I posted your original statement which says that the clear SEBO motor, due to the design of the side mount filter, doesn't have to pull air down through the bag. You revised this statement in a subsequent post to say that the clear SEBO motor draws air from the bag/bag compartment. I opined probably a result of the diagram you posted and I commented on. Thank you. On the surface, these two statements appear to be contradictory. I'll overlook the discrepancy and presume that you meant to say the clear SEBO motor draws clean air from both the bag and bag compartment [your revised answer]. I posted questions for you to answer about dirt by pass design and operations based on drawing air from both.
Carmine D.