My background is in carpet cleaning, but I'm about to expand into residential homes. I was wanting some advice on which vacuum to purchase. I like the versatility of a canister type over a upright ( which is what I use in my carpet cleanings) was wondering what input I could get on buying a backpack or a traditional canister style. Things I find important are : Hepa filter, no bags ( i like bagless), highest cfm possible, lots of tools (ie crevice, upholstery, etc...) dbm is not real important but I might consider it, cost is not really an issue ( ill spend the extra for quality), replaceble parts is a plus. Any advice would be appreciated. I like powr-flite. They seem to have some good backpacks, has anyone used theirs before? What would you recommend??