Chronics we’re my first ski. I ski the Mango 90’s now, and love them. Subjectively, I don’t think the flex felt too different, probably like a ~6/10 for both. That being said, still a completely different ski. The rocker profile and shorter effective edge on the mangos make skiing so much more fun for me, but it all depends on what you’re looking for, I guess.
I don’t know anything about the Frankenski that you can’t read on Moment’s website, but everyone I’ve ever seen riding them loves them, so there’s that.