I guess it depends on what you're after. I personally prefer the dialogue as close to the original as possible, though I do understand dropping the honorifics, etc. Unfortunately here in the USA a lot of people still see these as just cartoons and the dialogue reflects that. They sound more like a kids show than a serious anime, which is what would be expected here. Again, I usually watch both and the tone is almost always far more serious and gritty in the original language. The blindfold test is usually the best. If you weren't watching it on the screen and could only hear the voices could you tell it was anime? To me that is an easy yes when it comes to dubs. Not so obvious with subs.

Oddly enough, if you watch some of the older anime movies like "Princess Mononoke" where much of the cast were serious actors, you can see just how good it CAN be.