I don't like musicals, never have done. My mother watched an awful lot of them when I was a kid and it has put me off for life.
Okay there are a couple I like. Rocky Horror is one obvious example , Blues Brothers is another but generally I am not a fan of the format.
I do watch one from time to time though. I've seen Evita - well made but not my thing. I saw a musical of Jeckyll and Hyde some years back with Paul Nicholas and it was well done but I still didn't like it. I watched Moulin Rouge, at my wife's request, and thought it wa sokay for a musical but still I didn't like it. I've also encountered bits of others but never finished them. Hell I didn't even like Tommy the Film and I have been a fan of the Who for thirty years.
So Repo: The Genetic Opera had a lot to overcome if it was going to get me to like it. Okay it was horror which I definitely like, but it was still a musical.
Well I've watched it. I even managed to get all the way to the end. And I will agree it's well-made - good effects, decent acting and a cast that could sing. It was even a sf-horror tale, my favourite sub-genre of horror, but at the end of the day it was still a musical. And it hasn't changed my mind about the form.
If you are less biased against musicals I dare say you could enjoy. My wife certainly .She shares my love of horror, but also likes musicals - go figure!
I'm going to carry on avoiding them where possible. I'll keep watching horror though.