Within either sub or dub, there will always be that handful of bad voice actors. Anything video-wise created here in America would sound smoother because the animation is created to reflect that of the people who voice the characters. That would be the same concept for Japanese Animation. Yes, I do agree that sub does a greater good for anime because there's a natural flow, but there are some cases where even the Japanese actors don't act with great quality. I feel better to watch Pokemon in dub for example, because I feel the voices fit with better quality than that of the Japanese voice actors. The Pocket Monsters I feel do better in Japanese because they have a better, more coherent cry that sounds realistic for them. There are times where dub has done well for me and really, I wouldn't hurt myself if I had listened to what could be a poorly dubbed character. Dub allows me to pay attention a bit better and get a better idea instead of keeping my eyes on the sub as to not miss a single word. For me, it's not necessarily the quality that gets me to watch an anime, it's more so if I am able to follow coherently and can grab a better idea of what's going on. Therefore, I ultimately prefer to watch dub over sub.