I think they're very good. They're much better organized than most. His punching and muay thai combos with movement are very good. He also shows a crap load of drills, including reversals. One of the drills is the exact same armbar that Hughes used to finish GSP.
If you had to scrap one, I wouldn't really bother with the fight clinic one since around 60% of it is just the best drills from the other series.
On milkman Dan's now defunct MMA ranking thread, he had this...
General MMA
1) Matt Thornton: Functional JKD series 2 ****
2) Matt Thornton: Functional JKD series 1 ****
3) Frank Shamrock: Century Vision series 1*** 1/2
4) Pat Miletich: Century Vision series 1 *** 1/2
5) Tito Ortiz: NHB Freestyle ***
He puts the emphasis on striking. The groundwork is solid but basic, Mostly reversals and positional stuff. Its not BJJ but it's perfect for MMA which is what he's doing. Solid basic essentials....
Great set...