Performance will vary from machine to machine, I think, since the mounting on every machine is different. His Panasonic bag looks like a DVC cloth bag. DVC makes an excellent cloth bag for Panasonic/Riccar/Kenmore uprights. I used one once during my famous hotel test and the filtration was excellent.
Hoover has always offered a cloth type Y bag, but not very good quality. DVC should offer their version of Hoover A and Y bags. These modern cloth bags cannot be compared to traditional woven cloth bags, since its a multi-layer fused material, like a Kirby outer bag.
Some of those "Forever bags" are horribly undersized, like the Lux Discovery bag.