.......Thing about domestic vacuums is, regardless of whether it's bagged or bagless, you need to keep the filtration system clean [which often means washing the filters and making sure they're completely dry]. If you start using it for building work, hovering up loads of fine dust then anything, regardless of how well it's made, will soon get clogged up and become a vacuum that's crap. Loads of fine dust particles will eventually get through anything that breathes and clog the filters........
I did some work with Electrolux when I was at college (busy designing a vacuum cleaner for the new millennium
)
Key things to vacuum cleaner efficiency are twofold.
Firstly, as VB says, filtration. The secrets which go into vac bag design are up there with tea bag design and what they keep in and what they let through - and, needless to say are closely guarded.
The people who design the materials for tea bags are unsurprisingly the same folk who do the materials for hoover bags.
Secondly, the metal plate with grooves in it which sits on the underside of the bit you push along the floor.
Apparently there's only two or three companies worldwide that produce these plates and sell them on to vacuum cleaner manufacturers.
It's the minute differences in the radii of the grooves and slots of these plates which determine how much of your grot ends up in the bag and how much remains in your shag pile carpet.
Nothing to do with wattage, see-thru coloured acrylic components, or 'on board' tools - of which incidentally, Electrolux's informal view was 'toys which the punter asks for'.
ETA -
Nilfisk. I believe it's what they use to deep clean hospitals when they've finished building them.
Further ETA -
.... If people think Dysons are bad, then try some of the other cheap bagless vacuums. ....
Oh My Lord.
Mother had a Samsung one of these (prior to her current Miele), which played a little electronic tune whenever you turned it on (Why?)
And who's detritus chamber required emptying after hoovering each room. (Mum's rooms really aren't that palatial, or dirty)
It was the biggest piece of consumer durable §h!te I have ever encountered.
How people can manufacture stuff like this and not be in prison astonishes me.