This was a pretty enjoyable experience - not quite a romp but with some of those elements. I did enjoy it but not quite as much as the director and performers seemed to - it’s tricky to put my finger on exactly how and where, but there was a certain self-congratulatory air about it - perhaps not least by the over-emphatic use of the pop music of the period. It was almost as it Tarantino was well aware that this was one of his signature tropes and so felt the need to underline the fact - when in fact he did not. Sometimes less is more. But perhaps to expect THAT from Tarantino is flying the face of experience!
There was a strong degree of homage to a Golden Age of Hollywood which was, mostly, very nicely achieved, not least with the mixture of real and imagined films and TV series of the time. And I certainly got a good sense of what it may have been like on a Hollywood backlot. The soundtrack, apart from the general comment above, was a very sophisticated one with many many layers which, for me at least, made subtitles a definite plus.
The Manson connection was cleverly done and provided a darker streak running through the film -which was, at the end, very smartly shot out from under us. Definitely alternative history.