I dont think i understand how it could pass even while deflated? Wouldn't the child then just be basically sitting on the vehicle seat? I agree it has it place for what it can be good for like short trips ect...But i just dont think it would be anything i would ever need to use.
I think it passed while deflated because of the belt guides. If the seat were to deflate in a crash, or be deflated on any given ride, the shoulder belt may not be at the ideal position, but the lap portion of the belt would still be across the hip bones/lap and not across the abdomen. Besides, as mentioned, the chances of it becoming deflated or popping because of anything other than user error (which happens with all seats) are slim to none. This material is TOUGH. This is not the same material that flotation devices or inflatable beds are made of.
I think it will be a great option for lots of people, especially those who need to get three across! Traditional boosters with arm rests are rigid and often hard to squeeze between two other seats, or next to another seat. But this booster will mold to whatever is next to it, and it doesnt have rigid arm rests that will inhibit buckling/puzzling. Just like all seats, it's not going to be the right choice for everyone, but I think it will be good for plenty of people.