>>45715615SM has:
+ A Professor as the final Trainer.
+ Lusamine fusioned with Nihilego.
- Mina just rewards you a Fairium Z just by talking to her.
- Limited amount of Ultra Beasts, meaning you must care about Ultra Beast's Nature because there's no other chance of encountering another one.
- Available Mega Stone are those belonging to Regional Pokémon and Kanto Starters, meaning Pokémon like Hoenn Starters, Lopunny, Mawile, Beedrill, etc. aren't available in-game.
- No Move Tutor.
USUM has:
+ 100 new Pokémon, increasing Alola's Dex to 400.
+ Even harder Totem Pokémon than SM, like Araquanid, Alolan Marowak, Togedemaru, and Ribombee.
+ Mina has an actual challenge unlike SM.
+ 6 new Z-Moves, half of them are for Lycanroc, Mimikyu, and Kommo-o (which managed to fight the otherwise considered the worst Pseudo).
+ A recreation of Vermilion Gym which you can challenge daily.
+ Hardest Cover Legendary fight with Ultra Necrozma.
+ Unlimited amount of Ultra Beasts thanks to the Ultra Mega Ride (though reaching past Nihilego is a pain in the ass).
+ All Mega Stones available in-game.
+ Move Tutor.
