Yes, proper diagnosis is important. I bought one of these devices on the advice of my Chiropractor, and after he took ex-rays.
When I went to another Chiropractor he commented on how he was surprised that in spite of my old injuries, that my neck had a good curve to it even though I wasn't having so many Chiropractic visits. I told him I was using a Posture Pump and he said he also recommends the devices. He said that regular use of it was probably "saving me".
I think it would be very helpful to most, but they should get a Chiropractic opinion first.