6 weeks doesn't sound a lot, but with most bagless vacuums, dust starts visibly accumulating after the first couple of uses. 6 weeks and a clean filter is still impressive.
I have never had problems with dust clouds for bagged vacuums. Biggest problem I have had with bagged vacuums was the older paper ones which would split and the dirt would go everywhere, however the new, cloth type bags are much more durable, more hygienic and loose less suction and are generally more efficient. I prefer sebo bags in terms of sealing in the dirt, although it is a flap you have to put on yourself like the numatic bags, it cover the hole itself, rather than mieles flap which is spring loaded from the inside, and I found that my S7, the bag would accumulate near this flap and it didn't make a proper seal as the flap would close, but dirt would stop it from closing properly.
I did moan about the SEBO bags leaking pet hairs, although I have replaced the bag when I gave it to my sister, and she has 2 cats and 2 dogs and there is no leaking whatsoever, so maybe it was a "bad batch".
