I've only played sealed once and draft once so far, so this opinion is subject to change. But I like it. What stands out to me is the role tokens. For as long as I can remember, the advice has just been "don't draft auras; you're opening yourself up to card disadvantage." Roles are finally playable auras. They're fun and they seem pretty well balanced. The fact that a creature can only have one role at a time makes for interesting gameplay decisions and unique opportunities to generate value. [[Cursed Courtier]] in particular is a great design, really fun to make it work.
I agree with what you say about the archetypes flowing into each other, and I think roles are a big part of that. [[Unassuming Sage]], for example, fits in RW celebration and BW enchantment sacrifice and GW auras.