I personally have no issues with Seifer. I feel Setzer was more out of character than he was. I never cared for Rai an Fuu so I can't say I'm bothered if they were made more annoying than usual.

Tbh, outside of injecting Cloud and Squall with emo (Depeche Mode albums liquefied) I can't say I've been bothered too much by KH's version of characters. Hell I think Yuffie and Yuna are far more interesting and much less obnoxious than their true selves. I still dislike Aerith and Cid's english VA's though...