I've not read all the posts...but at home #2, I have one of those Kirby upright bagless vacs. The filters don't last very long and are VERY expensive. Vac is cheap, air filters are off the charts.
Home #1 we have a very expensive Kirby, but it's 20 years old and going strong (and you get a workout everytime you lift it!!).
I'm not advocating the Kirby, but only point is that the filters can cause an inexpensive vac to cost nearly as much as the most expensive one over time...
If you don't grow where you're planted, you'll never BLOOM - Will Rogers