It is, of course, a matter of preference, but, in my experience, dubs are almost always awkward in ways I can't ignore, 10s dubs notwithstanding. The biggest issue is timing. You have lines which are obviously padded with unnecessary words because it takes longer to say in Japanese than English and the opposite, as well as lines which are rearranged in strange ways. Of course this is the case with text too, but to hear that discrepancy spoken elicits a far more visceral reaction from me. This affects even the best dubs, Cowboy Bebop and Fullmetal Alchemist included, perhaps excluding The Cat Returns. But beyond that inherent challenge dubs have to face, many of them just seem poorly executed. I often find myself thinking "there are 10 more natural ways to say that line." I don't doubt that most of them a produced as fast as possible to save studio time ---> money. And then there's the issue of everything before the 10s, which is most of all dubs ever. The dub of Grave of the Fireflies, for instance, almost makes what's known as the saddest anime film of all time a comedy. It's that bad. Not to mention the fact that, in every dub, somebody has to have a "New Yoik" accent, whether they're in feudal Japan or medieval Europe.
There is the drawback of having to read the screen. Sometimes I choose to watch the dub, particularly if I watch with my youngest sister, who struggles with reading. Too, there are a few dubs I prefer to some degree, maybe because there's something special about them, or maybe because they're what I watched when I formed an emotional connection with the series or movies. But, on the other hand, sometimes the original cast is really good. After all, if we stepped outside the world of anime for a moment, it would seem strange and sacrilegious to me to dub Bergman's Winter's Light and Persona, which have some of my favorite performances in any movie. Where the movie or series can be said to be the sum of the director's artistic choices, the original cast can be very important if you want to experience the work as close as possible to what the director intended. After all, dubs are not just "English audio" but completely different casts with rewritten lines. Of course, there are things lost because I don't know much Japanese, which is why the emphasis is on "as possible."