It doesn't really matter regarding what bagged upright you compare to Dyson, though in my experience. The filters on SEBO may be higher than ones fitted to Hoover or Panasonic, or even any other brand - what matters more is the fact that ANY bagless vac requires far more filter care which is useless for anyone with a dust allergy.
I don't agree that filters have to be changed on a upright with every brand though, Marcus. The only manufacturer who brainwashes short cost consumable parts is Miele in my experience.
With the SEBO X, the microfilter can be brushed clean, giving it a bit more time before it needs to be replaced. However, on some models I know some owners don't even bother changing the microfilter, undoing the computer ties and giving it a wash before installing it back onto the plastic grid sock and using fresh computer ties to keep it on. A few sellers on Amazon UK are now selling SEBO microfilters in this way to cut down costs on selling the complete unit with the plastic grid sock.
I haven't ever done this, but I have had a microfilter that wasn't replaced for three years - I didn't notice any less quality of the vacuum air that the SEBO put out. But I did brush clean the filter at different times whenever it looked dirty. Did I sneeze when I came into contact with the dirt? No. I did sneeze however when removing the dog hair that got stuck up the cyclone bin of my Vax Mach Air!
Granted there is also a carbon filter for the SEBO X motor - but the carbon emissions are low and less harmful with the filter in place. Carbon isn't such a big issue from a vacuum cleaner when central heating systems produce far more of the stuff, just because you can't see it. Plus, other uprights on the market don't have a carbon filter like the SEBO, other than maybe a few Hoover bagless uprights.
I think if you have a dust allergy, then the first thing your home requires is a decent air purifier rather than relying on a vacuum cleaner with high grade filters alone.