Other bagless machines
Airspeed One is flimsy, I gave it to my friend. I'm seeing them in thrift stores already! I ended up buying a Bissell Healthy Home to vacuum the breezeway (I prevaccum my breezeway with it before using my Rainbow) from the Ollie's display models for half off instead.
The Healthy Home isn't any great shakes either but at least it feels solid and is more maneuverable.
I'd take a Fantom Thunder over either.
I have a DC07 and DC33 on the Dyson side, I hardly use either anymore and am actually considering unloading them. In my opinion the root cyclone works better, I never had any issues with it clogging, I'd firmly hit the upper part of the cyclone with the palm of my hand when emptying. My issue is they smell dirty, I don't know why but I don't get that with the Fantom Thunder, perhaps it has to do with the difficulty of getting the upper part of the cyclone assembly clean or the smell gets caught in the pre motor filters. I immensely dislike the narrow brush roller it gets clogged too quickly with hair.
With any of them my wife can't empty them because of her asthma, I have to empty them outside the house. Thus despite the inconvenience of the water we've been using the Rainbows (D4 and E Series) much more often, and once you get used to it, it isn't that bad, plus my wife can empty them. I've used the newest Rainbow and it's hose suction (while not formally measured) seems as good or better than any Dyson I've ever tried.
So I've got two Dysons but rarely use them. They're not bad, they're not spectacular either. They don't roll as easily as say the Fantom, and even if they have more airflow and suction, the brushroller hurts their carpet cleaning performance.