Pinball issues aside you really should watch this film. It's very funny, iconic and is as quoted as any cult film I can think of with the exception of Life of Brian.
Funnily enough I was listening to a Ricky Gervais podcast a couple of weeks ago and he was saying how much Spinal Tap influenced The Office.
I'm glad that themes like this and Big Lebowski get made.
Stern have Avengers and Stranger Things and JJP are doing Toy Story and
AP have Hotwheels so there are new themes to attract the younger generation (not sure them is the issue as discussed on other threads).
Anyway, I digress...... watch Spinal Tap if you get the chance.