Ended up getting a gtech which was fine for 2 adults in a small 2 bed house with wooden floors, but now we have kids and a bigger place we got a Shark corded and it is amazing. Literally the best vacuum we've ever owned.
Their tech can probably be imitated at a lower cost, but I won't take chances with the cheaper knockoffs, the tradeoff is not worth it.
I should add that I called Dyson once for my 7 year old wireless vacuum which was having battery problems. They mailed me a replacement completely free of charge. The upselling might be there, but the up-service also seems to be there.
2. My Kirby G3 is 25 years old and can suck a blonde through the chrome of a trailer hitch. How old is your Dyson? How long will your Dyson last? Can you get parts for it? Is it repairable?
The G3 does have bags but they're HEPA H11 and EN1822 that catch ultrafines, so there's negligible emissions and it's all contained in a bag rather than breathing that crap while dumping a baglass.