First off this isn't going to be a show for everyone. I saw someone ask, "it's about a guy with a chainsaw what's so special about it?". Yeah, that's true, but then again Naruto is about a guy with a fox, and One Piece is about a guy who stretches like rubber and we know how good those shows turned out to be.
Don't judge an anime by the premise.
For the manga readers this episode was a big treat. No matter what criticisms you have for MAPPA one thing you know is how well they portray the TONE of the show. CSM needs that half fun, half dark sort of tone, and I think MAPPA nailed it. Everything from the color palette, to the openings, endings, and soundtracks pretty much matched the whole tone of the story.
And the OP is a banger, ending is a banger and whoever chose the artists and music for this show deserves a noble prize.
I honestly didn't feel bad about the CGI. Except for that one wonky shot in the opening where a chainsaw comes out of Denji's head, the others were perfectly fine. I mean, come on people, this is about a guy who has a chainsaw in his head. The animators can't draw the animation of the chainsaw in EVERY single frame.
I always had doubts about Makima's voice actress, but I think I got over it. Sure, she sounds a bit young, but I still think she managed to give that creepy seductive tone the character needs.
Overall, 10/10 episode. Ignore the haters, the OP just hit #2 on trending, and the ending is #6 on trending in YouTube. This shows how popular this show is. And the more popular an anime is, the more hate it is going to get.
So ignore the haters, and watch this masterpiece for yourself.