BE WARNED! I purchased one of these from WOOT last year.
The decompression element is great, but the rush of blood pressure to your head is not good. I used my inversion table for a few months. Later in the year I started getting flashes in my right eye vision, and then a blind spot in my right eye. I ended up with something called a retinal detachment. I had to have emergency eye surgery or I would be blind in my right eye. I now live with a scleral buckle sutured into my right eye.
My ophthalmologist thinks there is a direct link. He said the detachment could be a direct result of myopia in the eye (near sightedness) combined with continuous raised pressure in my head from the rush of blood. After my surgery in late October, my prescription is changed dramatically in the right eye, and I am told I am at risk of having a detachment in my left eye as well. I also have to avoid doing things that raise blood pressure, or activities that involve jerky movements. (Sports, running, etc). I am very athletic, and this has changed my life ENTIRELY. To this day I'm not 100% sure that the inversion table aided in my detachment, but my ophthalmologist tells me there's a strong chance that it could have. Please ask your doctor/trainer/eye doctor about a correlation between inversion tables and retinal detachment.