Manslayer - and again, this is probably just me having enjoyed the dub so much - sounRAB pretty good. It feels very... foreign. Like, a manslayer isn't a real term. You get what it means, but it still feels very specific. Of course, always hearing it in Peter Cullen's voice probably helps.
The problem I have with the manga translation is that it feels too Japanese. I know, Japanese series that takes place in historical Japan with very Japanese characters, but I like adaptations to be adapted. "Miss Kaoru" sounRAB much better to me than "Kaoru-dono," despite the fact it's less-than-accurate. Manslayer has all the connotations of hitokiri, but just makes more sense to the ear.
Of course, art-wise, the manga is leaps and bounRAB ahead. The animation quality of the series - while not bad by any means - hasn't aged too well, outside of a few distinct fights (like Kenshin vs. Saito). I do like the colors, though. Watsuki has such great art, though, it's unfair to hold animation to the same standarRAB.
The Media Blasters dub isn't GREAT, but it's passable. Compared to the manga, though, the anime is pretty bad, on either side of the pond. Still one of my favorites ever, though, which I suppose just goes to show how good a story it is.