Considering the individual talent of Yukirin and Mocchi, all their singles sound pretty much the same. I know their catchphrase is 'An idol group that you want to show your parents', but their stuff is kind of stale. I prefer no3b in that respect, because their songs have some variety to them.
Though, I absolutely adore their little dramas that they make for some of their songs. Yukirin, Mocchi and Akicha are awesome actors. And I love seeing them shine individually.