Seymour's voice bugs me cause he always sounds like he's doing a Steven Segal impression which makes all his dialogue unintentionally more funny than they should, not to mention his god awful character design.

As for Cecil's, I will agree for the DS version of FFIV but he comes off a bit too emotional in Dissidia and half the time I felt like he sounded less like the Cecil from FFVI DS and more like Sasuke from Naruto.

Speaking of VA's who did bad in one performance and then rock in another is Hedy Burress better known as Yuna from X but also plays Agrias Oaks in FFTactics:WotL. I feel she did a poor job with Yuna cause she tried to hard to sound like the original Japanese which doesn't work in the English language as it comes off monotone and unemotional or scatterbrained as well. Yet her VA work as Agrias is so damn good I was literally floored that it was actually her.