I love a bit of both- my current band goes from the classic ZZ Top tunes La Grange and Cheap Sunglasses to way more complicated lines like Working Man and I'M Your Captain. Keeps me on my toes.
I love to listen to Jaco at times, but have no desire to play like him as most of what he does, is not rooted in rock. It is Jazz changes type playing.
I think Marcus Miller is the greatest slapper bar none- but do not try to get up to his level of proficiency with it, as there is little to NO need for that type of playing in 99% of bands anyone would play in. His style works for him, because he has arranged the tunes to work with it, he does a bass solo, than the sax takes a solo, then the keyboard, then they play the unison riff, etc. Most bands you would play with it simply aren't arranged like that.