Decompression for Back Pain - Does it work?

Hi all -- I'm interested in trying the back decompression machine that chiropractors are tauting as helping those with back pain. I was injured in a fall two years ago and still am trying to recover. I've heard that the decompression machines will help those that even surgery does not help.

If you've used the machine and had success (or not), I would really like to hear from you. It's quite expensive and I don't want to try that route until I know if it will work. They claim they have about an 80% success rate.

Anyway, I'd love to get any feedback. Thanks