Down B buff was nice, now you can use luma right after eating a projectile.
Fair buff was pointless. characters still fall out of fair and the reduced air lag doesn't really give you any additional options.
F smash buff was also pointless, the move was already super strong, just hard to land in a practical way because of luma's behavior.
Dash attack buff was pretty nice actually. It makes boost grabbing and a few other attack cancels more useful, but ultimately those never lead into anything big.
Luma respawn buff was ok, but not too useful in 1v1
Grab speed buff was ok
Luma having less hp doesn't matter since anyone can kill luma in 1-2 hits regardless of hp.
Ultimately rosa is still a hot mess, the buffs seem significant on paper but in practice they didn't really help much in the grand scheme of things.