I have a Kirby Ultimate G. I DOOOO love it, although I also feel like I got a little suckered into buying it. My husband was in Iraq, I'd just had a baby and WOW! How this thing got rid of dirt and allergens!! I NEED THAT! I probably could have found something else comparable for less, but haven't looked.
All in all, I love my Kirby, have used it SEVERAL times to shampoo my carpets in our house in Denver. The rental we're in now has all hard-wood floors so the attachements work great here.
It's pretty heavy if you have stairs you have to haul it up and down, but it's got a powerful motor. I've had mine for almost 4 years and have never regretted buying it, but like I said, I have to believe there's probably something out there that does the same work for a lesser price.
Oh, yes! And I have taken it outside to vacuum out the cars. Changing the heads and the belts really isn't that confusing if you've been instructed or have a manual. My husband is amazed at how quickly I change from regular vacuum heads, to attachements, to shampooer.