The tone of those series is obviously different but they follow the same plot beats: perky blonde girl shakes the world of the more serious brunette, blonde develops strong feelings for the brunette while brunette struggles to understand these new feelings blondie is stirring in her, conflict and misunderstanding happens, things work out in the end and they become a lovely couple.
Girlfriends is different on its structure since it dealt more directly with the implications and consequences of coming out on top the usual romance tropes. I guess that is what I find distracting, Morinaga's works of late are just different takes on the same romance tropes, lacking that layer that made Girlfriends so special.
Mare is the anomaly on Morinaga's output but also is one of her earliest works.