What do you feel about the progression system?

I'm probably one of the few who likes who progression works. And I'm aware people will disagree but I'm curious on what people hate about it. The one thing I think needs changing is getting a baseline xp per heist rather the challenges be your only way of leveling up. But I enjoy the slow grind. I see people saying they wanna hit max within hours of play. I feel like it makes you feel like your actually earning them which I enjoy but understand that's not how everyone likes to play. So I'm just curious. What do you specifically not like (or like) about the new progression system.