I wouldn't say Sun and Moon are difficult, personally. I plowed through the game without a single loss until Kukui. Aside from that though, I agree. Sun and Moon is the best Gen/Main Games in a long time. I love all the features they over hauled and how much easier it is to navigate the mechanics. I just- gah I love everything about Sun and Moon.
I enjoy the game, but it wasn't the best.
The trials was really interesting, and it was challenging for some trials. However, I found a way to easily defeat the game with a breeze is to have a certain types of pokemon (i have all eevee evo as a team LOL). Story wise, it was okay. Capturing the legendary is too easy. But I do enjoy the exp share, because I don't have the patience to level grind all my pokemon.
After completely the game, I got super bored very quickly because it was so limited.
I'm still bum there isn't like a fun mini game to play with your friends. The festival doesn't really count. haha.
Now the game is just sitting there, I may want to pick it up again. Plus I feel like the clothes style were limited. Heh. I don't know.
As it was my first real Pokemon game I played, I enjoyed it a lot. Yeah, the game seemed short on the story mode, but when it comes to leveling up pokemon like I was doing to mine, it takes a really long time (like 8 to 10 days to max out a Pokemon).
When it comes to my interest in Pokemon, I've been more in favor of the spin-offs. But Sun and Moon was worth giving a try.