I like every single Love Live series, but I must admit that Love Live! Sunshine took a very large inspiration from the first Love Live! cast. I could probably write the characters they're most similar with :
Chika = Honoka
You = Kotori
Riko = Maki
Ruby = Hanayo
Hanamaru = Rin
Yoshiko = Nico
Dia = Eli
Kanan = Umi
Mari = Nozomi
The characters seemed very forced to be like the first Love Live! cast which was very unfortunate because there is a lot of ideas of the girls to become unique from the first Love Live! cast.
The story was deffo a Love Live! part 2. Because both of the main plots are about their school closing down due to low student count except this one is more forced. It also doesn't make sense how a character in the series (Riko) was introduced and how she was able to get into the school.
Compared to the first Love Live! series, the animation here improved, but it looks weird one and then with the CG.
The music of Love Live! Sunshine was a lot better than the first series. It is a more diverse music concept and the music quality is better.
In m opinion, the anime is alright. The first Love Live! series was a lot better though. It's just like Mean Girls, the original is a lot better than the second one. except Love Live! Sunshine is quite an okay series