Dump out bag Sanitares
I got a bit of heat when I made an entire thread about my disdain for machines with dump-out bags, and while I may not have taken some things into account then, for the most part, my opinion has stayed the same.
I've seen so many Sanitares and Sanitare clones in businesses like hotels, grocery stores, schools, and others, and I'd say they aren't ideal for any of them. For one thing, they're a mess to empty, so you really have to take them outside to do so (as you probably should with all bagless vacuums). I'm also distrustful of how well they filter. I've heard that some actually filter decently, but again, if you empty them indoors then you're just gonna reintroduce everything you picked up back into the air. I've also seen them with caked dust around the bottom half of the bag, implying that they aren't filtering well.
The only application I can really see justifiable for them is for carpet installation, where the carpet is brand new and you wouldn't want to burn through bags. For every other application, though, a bagged vacuum with a HEPA bag or a sealed HEPA bagless vacuum are the only acceptable options in my eyes.