Thank you Chase and Fred,
I didn't mean any offense. I remember watching paid infomercials years ago which was the first time I ever saw a bagless vacuum. I caught all 4 Fantom Technologies infomercials for the original Fantom Thunder, then the Fantom Fury, then the Fantom Lightning and the Fantom Cyclone XT. I thought the machines looked really neat cause you could actually see what you were pulling up. Then I eventually caught presentations of the Fantoms on The Home Shopping Network. Chris Scanlon used to do the presentations and she didn't use any glitter, sand or anything, she just vacuumed a rug and showed viewers what she got. Later I heard about Dyson and saw that the UK had them but not in the U.S. They looked like a completely revolutionary awkwardly designed machine. They finallly hit U.S. market and people were very excited at first including myself. But a closer look in the store and there were some things about them that turned me off. Of which I can't say that I have found any vacuum on the market to be perfect. There are atleast 2-3 things minimal on each one I've ever used that I want changed, whether its wheel material, agitator bristle stiffness, agitator cavity width etc.
I've done housecleaning for years and through my own household, relatives, work environments and more I've used many many vacuums. You have an interest in Dyson along with millions of others in the U.S. and around the world and that's fantastic. I have only used 2 models. I clean a house with a DC07. The husband likes it, the wife and myself do not so when her Kenmore Progressive canister died, we had a lull where I used mainly Dyson and a few months back she bought a Hoover S3670 Windtunnel bagged canister. Strangely enough the Dyson struggled the mostly on cleaning area rugs. I was able to fit a generic bare floor brush on it for doing laminate and tile floors but the agitator wasn't working good on the carpets so I brought my own Hoover PowerMax canister over during the lull.
The other Dyson I've used was a DC21 powerhead canister which I trialed at Sears. It was different, but I didn't mind it. I think if the wand rested in an upright position rather than having to lean on chair I may have liked it better, along with the fact it was out of my price range.
Over the years I have worked on Kirby, Filter Queen, numerous Hoovers, Eurekas, Dirt Devil, Bissell, Orecks, Panasonics, Kenmore, and possible a few others I can't think of right now. The only work I've done to a Dyson besides general use was wash filters as we noticed a definite decrease in suction. I read the Dyson DC07 manual for my client trying to troubeshoot why it wasn't doing well on carpet and the manual did not even mention the agitator, nothing about a clutch, belt or even replacing the brushroll. Sorry that I cannot offer any further assistance with your DC18 but I do wish you the best of luck getting that corrected and hope it is not too costly.
Another brand I haven't had luck with is Oreck. I have tried 3 different models of his lightweight XL series uprights. Not the XL21 just the original series. I experienced allergy flare ups during usage with each, along with difficult maneuverability and not so impressive dirt pick up. In repairing one, quite a few of the tabs on the inside of the housing where screws go into had broken off and were laying inside the housing when I looked inside one. I have heard good things of Oreck 21's and the new Quest Pro power head canister is neat. I also trialed that at Boscov's.
If you've never tried a Hoover Tempo, I would however encourage you to try one at your local vacuum shop or I tried one at Boscov's Department store. For that price the power is really amazing. It doesn't state Windtunnel Technology anywhere on it, but the agitator cavity is the same as a Hoover Windtunnel Supreme.
I look forward to being helpful with some of your vacuums if any issues should arrive. I see you have a dirtcup Hoover Decade 800 in your collection. Those are great machines, and the dirtcup model was a rarity. I love the dual headlights on those. Our household had a Grey Decade 800 for many years, I was always ensuring that the air freshener scent tablet was fresh when I was young.