Going by just the movies, Zonakin's fight with Dooku was faster, but the Count was at least able to put up a semblance of a fight, matching Anakin blade for blade, even if he was being forced backwards. Vader, meanwhile, lasted longer, presumably in part because Luke wasn't really focusing on his technique at all, but he was utterly helpless in any capacity. I think it seems like this is the case:
Zonakin is more focused and a better duelist; however, Luke's rage was more focused on destroying the other guy, in that it utterly cripples even Vader through the Force (notice how he's stumbling in disarray even when Luke isn't touching him). I can't compare novelizations; I haven't read the RotJ passage.