Neither of them were emotional in the Manga. It's the anime that has everyone feeling that Itachi's was more emotional. We should revisit this after color and an OST is applied to Naruto's farewell to Minato. Then we can discuss who's was more emotional. U_U
itachis goodbye was essentially "im perfectly ok with you, my evil psychotic genocidal brother. have fun exterminating everyone i care about and plunging half the world into darkness. k thx"