What did I miss?

It's a Tarantino movie. You either enjoy them or hate them. I really like Pulp Fiction and in that aspect there are similarities between the two films in progression, there will be one story going on then it will cut to a tv scene set within the movie before jumping back to another character sometimes throughout the movie. It makes for an interesting viewing experience though I can imagine that it wouldn't be everyones cup of tea/coffee/vodka/what have you. I watched it in the movie theatre and my thoughts after viewing it were that it was pretty good. Without spoiling plot points.. It kind of trys to blend the real historic side of things with what was going on in Hollywood at that time that it is set within, in terms of the 'murder' narrative that gets fictitiously portrayed. I figure that It's really the kind of movie you appreciate over a glass of nice liquor or whatever you have. It wasn't the funniest, though it did have a few great scenes. I wouldn't imagine it was trying all that hard to make people fall off their seats laughing so I didn't personally walk into it expecting to see that.  I think with 'Once Upon A Time In Hollywood' the comedy is secondary to the movie itself in what it's trying to do, which is give off the vibe of that time setting
while it's plot develops as it goes along.

I think it fits/works well overall for a quentin tarantino movie.

It also gets an extra point in my books for the reoccurring J.Cash Portrait.