A tad off-topic, personally for me, in I"S, I felt there wasn't any mess. Iori was always THE girl in Ichitaka's heart. The others provided some distraction and made things murkier for the Iori-Ichitaka dynamic, but in the end, his heart was always with her.
The ending for I"S was trite though. I mean, they even had an alternate ending.
As for Ichigo 100%, things are in a right mess now.