William, I respectfully disagree with you about both of these canisters.
As for the Duros, when it was being made, it was manufactured by Sanyo in China, NOT Japan as you stated. I know this personally as I actually got a Duros canister from the local vac shop for free....it was a abandoned repair....and reused the motor in another vacuum. Also, the bags were VERY EASY to find while it was still produced, as the vacuum was primarily sold in Walmart and in Home Depot as the Maytag Legacy. And they were paper micro filtration bags, so the filtration was as good as any other bagged canister in it's price range. You could also improve the filtration by saving a Hoover SR bag collar and using it on a Type S Hepa Cloth bag. Speaking of the vacuum not having a bare floor tool, it didn't need one....it had a powerhead on/off switch on the hose, as well as a powerhead on/off switch pedal on the powerhead. And it actually did a decent job picking up dirt from bare floors since it had strong airflow and the powerhead brushroll opening was very well concentrated. It also would have been easy to use a generic Miele 35mm floor brush if desired. The only real issue the Duros had was the quality of the hose....it had a tendency for the hose material to come separated from the machine end. Also, the tools were only average, and the powerhead wasn't that good at grooming carpets....only slightly better than the compact Miele SEB217 & 213 powerheads. If you didn't need a exhaust HEPA filter, had only low pile carpeting and didn't mind buying a adapter and some generic tools, it was definitely a good budget alternative to a Miele canister with the same cleaning performance.
For the Bissell Digipro, I can only say good things about them. Yes, you would have to get bags online or from a vac shop, but they are good quality paper microfiltration bags. I have also seen some people use a generic Miele GN bag, which them being HEPA cloth bags would help with filtration. They also had a HEPA filter on the exhaust, unlike the Duros. As for the quality of the vacuum, yes they were cheaply made, but appropriate quality for it's price range, and you still see them being sold second hand today. I also feel the powerhead was better than the powerhead the Duros used....it seemed to groom carpets a little better, plus it had height adjustment and a telescopic wand. personally. I personally would have taken the Digipro over the Duros for these reasons.
Rob