He's supposedly the most-influential American anthropologist.

Yes, but that's because he was doing stuff in the 50s and 60s, when there were a lot of old theories that were ripe for refining and overturning. He made a name for himself by saying a lot of things that seem obvious to us today -- questioning structuralism and functionalism as dominant paradigms was big news in the day. I would say that his work on theory is not worth the trouble it takes to get through it, but I have a low tolerance for bushwhacking through tangled prose. When you get to applied cases, he does make more sense, and can be engaging. I remember Peddlers and Princes being worth reading, although I think he had a good number of page-long paragraphs there too.