FF14 EN client supports original JP voice as well as subtitles, and I'm sure some of you are already aware, SE hired some of the best the JP voice actors for FF14.
Take a look at these 2 characters for example:
Minfilia: Miyuki Sawashiro
http://en.wikipedia.org/wiki/Miyuki_Sawashiro
Y'shtola: Ai Kayano
http://en.wikipedia.org/wiki/Ai_Kayano
If you are one of those who prefer the original voice acting (no translation, no casting actors in another language involved), you should definitely give JP voice a shot.
My personal opinion is that it changes the tone of the game and the characters become far more likable. Unfortunately I did not like the EN voice acting at all.
Just for the record, I have no bias because Japanese is not my native tongue nor is English. Games like MGS I actually preferred EN voice acting.
So when you get a chance try it out! You might like it :-]
edit:
This is true, some contexts are lost or altered in translation (though it doesn't bother me because I can understand Japanese so I can just ignore the EN texts.)
Still, wouldn't you agree that all things considered JP voice + EN dialog text is still far more enjoyable than EN voice?