>>45700408Sour Crystal brings a lot of QoL to Crystal like the pager system which is basically ride pokemon from gen 7 in order to get rid of the need for HMs, you do still get the HMs. It's really cool. But from what I see it doesn't really do anything about teams or levels, I'm still in Johto though.
Polished Crystal is more of it's own thing. Like it takes a lot of things from HGSS, it changes a lot. It adds more trainers, changes teams, and tries to fix the level curve. But again it does drop Johto pokemon and adds in a new rival, Lyra, which is enough to annoy the boomers on /vp/. Still though, Polished does a lot of cool stuff for Crystal, it even has a nuzlocke mode.