These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Furthermore it played for 62 WEEKS STRAIGHT there when it first came out!
Hilarious in Hindsight: Swan programming Winslow a new voice almost becomes funny in an era full of auto-tune and heavily processed vocals that sound synthetic.
Moral Event Horizon: Subverted. Judging by the tape, Swan in 1953 seemed like a very narcissistic and egotistical hedonist but ultimately not a monster, and had been producing gold records (presumably not stolen ones) since age 14. At some point after his Deal with the Devil, he obviously became the horrifying thief and abuser we see him as, though nothing in the deal itself said he had to. Alternatively he could've been that way all along, and we just didn't see it.
He openly states to Philbin that he abhors perfection in anybody but himself; he was very vain to begin with, wanting to commit suicide because he didn't want to grow old and lose his good looks; when the devil asks him if eternal youth is worth his soul he replies "What soul?". Swan was a complete monster all along. He's not above using people to get what he wants, and everybody is a tool for him to use and abuse.
For the first hour of the movie anything Winslow did was at least understandable. But when Phoenix's performance is about to start he murders the totally innocent stagehand operating the spotlight so he can man it— and he murders Beef for no better reason than he was in the wrong place at the wrong time— showing how far he has gone in his anger and obsession.
Retroactive Recognition: For the Whose Line? fans, there's Archie Hahn as one of The Juicy Fruits. In fact, it's a little strange watching him in this film, and actually sing really well, while on Whose Line?, he... well.... didn't.
The Woobie: Winslow, especially pre-Phantomization. He's impossible not to want to hug and be friends with.