"Some generic bags are ok, but mast are crappy"
Will, first of all, I respect your decision to use genuine bags if you feel the need to protect your vacuum & keep your warranty valid. In my case, however, any warranty the vacuum had is long expired, so I feel no need to pay a premium for the manufacturer's bags. As for the quality of generic bags, I will respectfully disagree with you. What you are not understanding is it's the bag collar & how the bag is installed that causes dirt leakage, NOT the bag material itself.
Miele generic bags are available in 3 or 5 ply HEPA Cloth material, depending on the price per bag & manufacturer. The amount of bag layers determines the bag's ability to store dust within the bag material, & how quickly the material clogs with dust & reduces the vacuum's suction & airflow. If you ever try to reuse a bag by taking the dirt out thru the bag collar, with a paper microfiltration bag there is very minimal dust left in the bag, but with a HEPA Cloth bag even after you empty it you will notice some dust you cannot get out of the bag. That dust is actually trapped within the bag layers & cannot be removed. That's why you can shake a HEPA Cloth bag & restore the suction & airflow of the vacuum, shaking the bag loosens the dust from within the walls of the bag. Most vacuum manufacturers, such as Sebo, Riccar/Simplicity/Carpet Pro/Fuller Brush, Hoover, Electrolux AB, Aerus Electrolux, Panasonic/Kenmore & Zelmer use 3 ply HEPA Cloth, the exceptions being Lindhaus & Fakir-Nilco which use 5 ply HEPA Cloth, & Miele's 9 ply AirClean HEPA Cloth bag. So right there the Miele generic bag manufacturers are making bags that match the quality of most of the OEM manufacturer's bags.
Take a look again at the video you linked to, "Miele plus s251i Repair Tune up. USA Miele motor history". Notice how all the dust is at the top of the bag compartment on the bag door & the top of the motor housing & there is only a small amount of fine dirt on the bottom of the compartment? That is because the owner used a bag with a cardboard bag collar which did not make proper contact with the bag door tube. There is no discoloration of the bag or any damaged seams, so it is clearly not the fault of the bag material. Also look at the video "Miele S558 Red Velvet Canister Vacuum service & Repair", see how when Alex opens the bag door how the cardboard collar on the bag appears to be warped? This is exactly the reason why I do not recommend using generic Miele bags with cardboard collars - they do not have the rigidity that the plastic IntensiveClean & AirClean collars have to ensure proper contact with the bag door tube & not cause a issue with dirt leakage.
There are other factors besides the bag that can also cause bag leakage. If you look at the videos "Miele C3 s8 Kona "soft carpet" Vacuum Repair" & "Miele Compact C2 Electro+ S6 SDAE0 SDCE0 -Vacuum Cleaner Repair", the cause of the leakage in these vacuums is a bent, warped bag holder. Alex claims in the Electro+ video the generic bag caused the dirt leakage, but in the Kona video it has a genuine Miele AirClean bag installed, so that rules out the bag from being at fault, & using a generic bag also couldn't have caused the damage to the bag holder, in both cases that resulted from the owner abusing & misusing the vacuum.
You might also not be aware that Miele's OEM bags themselves are not perfect. If you read this Vacuumland thread from Gsheen, "Miele bag leakage ??", you will see the Miele HyClean bag in the S7 upright leaking all over the place in the bag chamber, yet the bag is installed perfectly in the cleaner. As he stated in that thread, the dust leakage is CLEARLY coming from the bag material itself leaking. This is the correct & genuine Miele bag for South Africa, the AirClean bags are only for North America, every other part of the world uses the HyClean bags. Also, if you read reply #50 from piano_god, he states he has seen dust leakage from the previous Miele IntensiveClean bags. So, as you can see, under the right conditions even the OEM Miele bags can cause issues.
Finally, take a look at these photos of my Simplicity Gusto. I have modified the vacuum to take Miele GN bags by removing the bag holder & wrapping the bag door tube with clear packer's tape to increase it's diameter. Before installing the bag all that is necessary to do is snip off the bottom of the bag collar & then mount the bag directly on the bag door tube & tuck the bag in as I close the bag door. The bag fits onto the bag door tube VERY TIGHT, there is absolutely NO chance for the bag collar to come loose or move around to cause any issues. The ONLY way there would be any dust leakage whatsoever in this bag chamber is if the HEPA Cloth material of the bag itself was leaking dust. Now - tell me, Will, where is the dust leakage caused by using a generic Miele bag? There is NO DUST AT ALL whatsoever in this bag chamber, on the pre-motor filter, or on the Hepa filter on the exhaust - just carbon dust from the motor.
I think these photos should serve as proof that, when used & installed correctly & with care, generic Miele bags will NOT cause a issue with dust leakage in the bag chamber or on the pre-motor filter. The only advantage the OEM Miele AirClean bags have is they allow the cleaner to maintain suction & airflow much longer, until they are 3/4 full. However, that issue is easily solved with the generic bags by taking them periodically & giving a good vigorous shake to loosen dust inside the bag. While I occasionally use OEM Miele AirClean bags for certain tasks, I cannot justify paying $4.38 per bag for everyday cleaning, when a generic bag for about $1.50 works just as well.
Rob
https://www.vacuumland.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?14793
