The problem is a pissing match of "school politics" has evolved around this very issue. On the one side what they call "Original JKD". This is the last form of JKD Bruce Lee taught closed door students and certified them in. The instructors of this style (yes it is a style) say that the Tao of Jeet Kun Do is on the practitioner. In essence when they become skilled enough they take what works best for them from the style they were taught. Thing is the JKD Lee taught at the end was not the same as the JKD Lee taught Inosanto in the beginning (Guro Dan was his first student and first to be certified in both JKD and Jun Fan again.). Guro Dan in one interview said there were periods where Lee was changing JKD on a monthly basis.
JKD concepts also keeps the JKD essence on the Instructor side. As
@Charlemagne said, "Original JKD" often uses Savate style kicks, JKD concepts has more Muay Thai style kicks, the Instructors have continued the evolution of the art, while keeping it grounded in the roots of Kung Fu that was the original Foundation of Lee's JKD.
Btw I don't think one is better than the other I think they both honor Bruce Lee but in a different way. I think "Original JKD" honors Bruce Lee directly by teaching the JKD he taught at the time of his death. Having read the Tao of Jeet Kun Do many times I think JKD Concepts honors Lee indirectly by still evolving the art and thus honoring his expressed Philosophy.
However sadly, and ironically, the JKD community followed in the Foot steps of the first art Lee learned in part, Wing Chun. We have people not simply saying we follow in the spirit of Yip Man (who actually modified the WC he was originally taught over the years) instead we have people arguing over whether Wong Shun Leung, William Cheung etc is teaching "true" Yip Man WC. Silly arguments. It's like two brothers arguing over who is Mom and Dad's "favorite."
PS to say "in part" was not an insult to Lee but it is a fact that his parents sent him off to the US before he had completed learning the system.