One of the most obvious things I'd point out is that jazz drummers have been doing up tempo stuff way before metal came onto the scene. You can hear examples of Max Roach, Jake Hanna, Louie Bellson, Tony Williams etc etc blazing at upto 400bpm for a good 5 minutes at least. I think my best answer to your question would be to paraphrasis Earl Palmer, I can't remember the exact words, but he said that you gain a certain feel for the kit which you wouldn't get from solely playing rock. For me it goes way beyond licks and beats you can take from jazz and put into rock. What I've learnt from jazz is about musicality and subtlety eg how something as basic as quarters on the ride can be phrased in different ways. You learn how to approach time playing: do you play fractionally ahead of the beat for a more driving feel, behind for a more laid back feel or dead on. Working on jazz is extremely important for me, after all it is the history of the drumkit. Even double bass came from a jazz drummer, Louie Bellson. Elvin Jones hit the drums hard just like metal drummers (he could play softly as well), he converted pure passion and emotion into music, that's what you learn by studying the great players of jazz.