I, too, own the VX-5000. Once you get the hang of it, it really saves time on interior detailing. It's pretty expensive, though, but starts to pay for itself as you use it. For example, you won't need to purchase glass cleaning product anymore because the steam works perfectly on its own. It's great for dirty carpets and fabrics but not for anything too filthy as you'd be better of with an extractor for those jobs.
I've also used it for engine detailing. Works well as long as you can find lint-free towels. Unfortunately, it's gone up about $100 since I purchased it - but still a good option if you are able to drop $800.
-J