I saw Jason do the In The Name Of My Father tour back in 1997 twice. It was great to see him playing Zeppelin tunes, but neither Jason nor the rest of the band were in great "shape." I am sure even Jason would admit to that now. It was really sad in some ways.
When I saw Jason with UFO in 2004, he was 100% clean and sober and like a new person. I really, really hope he stays that way. His Dad would want him to, no doubt.