It depends on the dub, as well as the series I guess. I find dubs by Funimation to generally be well done (generally), but it also depends how Western-oriented the content is. I prefered dubs for Fullmetal Alchemist and Fairy Tail for that main reason. I tried the subs for both of them, but it just didn't seem natural when the content is so Western, or when the spoken language in-universe is intended to be English or another European language.
However, there are some horrible dubs out there, and some where English feels unnatural to me for the same reason as above. I liked Inuyasha and Ao no Exorcist much better in Japanese with subs. I have dual-audio versions for some of my anime, like Darker than Black and Mawaru Penguindrum, and I didn't bother watching either of those dubbed.
Though I think first impressions play a big part on how natural these voices might sound.
NNID: Zephyr25 / PSN: Zephyr--25 / Switch: SW-4450-3680-7334
