Sazh is the best, yeah, and Lightning is very good too. Snow has some very cliched lines, so it'd be hard for anyone not to make them some awkward, but it's quite allright. Vanille seems a bit out of place, but maybe it'll be fine later on when she finds her place in the group. Hope's voice is a bit whiny and annoying, but so is his character so the voice actor is definitely doing his job.