As stated before, I have no first hand experience with the AF-1 and if it doesn't need to be re-spooled the "easy" way like a bubble magus does via staples, then that's a good design (in which case I would be very happy to be wrong with my assumption). The more well designed equipment we can have in the hobby, the better it will be for everyone in the hobby (especially if more affordable).
This video unfortunately doesn't really show it being re-spooled while in service (I personally wouldn't put the effort to pull the entire unit out just to put a new roll for example if required for it to be "easy")
For comparison here's some random person on youtube who did it from the 1 minute mark and finishes at the 9 minute mark in the video while explaining stuff. If he didn't take time to show parts/do explanations it would've been less than his ~8 minute roll change for sure.
Not entirely sure how you're getting 28 days remaining on the left unit but a whole roll is ~1368 inches.
If we round up consumption and do 1368 inches/5 inches a day = 273.6 days (we'll say 273)
That's over 9 months for a measly 12 dollars in my use case on the left unit.
If we deduct the current quantity used we get 1044 inches remaining which using the same average would result in 208 days remaining worth of life.
The paper shredder on the right? 1368/22 = 62 days or 2 months for 12 dollars (all numbers are rounded in your arguments favor)
Personally I can't complain about my "paper shredders" considering I run a red dragon 200w hp + vectra l1 for tank turn over flow and go through at least 8 oz of frozen food + various dry food on a daily basis for this particular tank.
One final bit as well, filter roll longevity has nothing to do with X Y or Z brand filter roller and everything to do with roll micron rating + flow (primarily tank turn over) + bioload(fish quantity + feedings).
As any one of those factors increases, the consumption will naturally increase in a non linear fashion
Similarly the opposite is true where if those factors decrease then there will be a non linear decrease in consumption.
Can you guess when spawning events happened in this example?