I had one of these back when I used to clean houses for a living. It's a nice vacuum, fairly quiet with great suction, and unlike some canisters it rolls round easily and doesn't get in your way too much. The dirt capacity is massive, so I mostly used it in large houses with vast areas of carpet and lots of pet hair.
Never did like the hose setup much though. The hose doesn't swivel fully at the machine end, and doesn't swivel at all where it meets the handle. Only when you have to keep stopping to untangle it do you realise how much we take double-swivel hoses for granted these days. The pigtail connections for the power nozzle are a pain too, no good for jobs where you need to frequently change attachments.
It does filter well, hence the name I suppose, but it's probably the messiest vacuum to empty that I've ever come across. It works well, but for me it just wasn't easy to live with.
Cheers,
Kirk