I got gravely injured on DRX 9000. You may notice it right away but if you have any SI issues (or event if you don't) SI ligaments will be weakened with the treatments and may later fail. This is what happened to me. The issue with many providers is that you will be placed on the hot bed before the treatment and iced/lasered after the treatment, this will mitigate the pain for the duration of treatments. I also was under a lot of stress at the time and did not notice that I am being injured.