The issue with anime dubs is that I find the acting atrocious. For one thing, too much effort is made to match the dialog up with the lip movements. (Sometimes the dialog bets a lot better when the character is facing away from the camera or has a really thick mustache.) I’m just mystified however when I hear a dub with an actor I know is talented and it still sounds lame.
One exception, kinda, Miyazaki says he prefers the Jean Reno dub of Porco Rosso to the original. Of course, I don’t speak French either, so I’ll still need the subs.
First Ghibli movie I saw was Ponyo at a little hippy volunteer run cinema- so hippy that the only person who knew how to work the projector properly hadn’t come in, so we all watched it in Japanese, with French subtitles.
They did let us in for half price, and as pointed out by the ticket seller, it doesn’t make a whole lot more sense if you know what they’re saying 
If the dubs are done really well, then dubs. But dubs are almost never done well, so almost always subtitles.
The absolute worst was when I rented Crouching Tiger, Hidden Dragon, and the default for some reason was dub and sub… and the translations were slightly different. It was maximally distracting for me to see understandable words, and hear understandable words, and they didn’t match.
The most amusing was a movie called Jesus of Montreal, which was (unsurprisingly) set in Montreal, with all of the characters speaking French (so, of course, I was watching it with English subtitles). But there was one scene in a hospital, so one of the main characters was talking to the doctors in English, and that section had French subtitles in the original movie, for the benefit of the original francophone audience… and the actress’s accent was so strong that I actually found it easier to read the French subtitles than to listen to the English audio.
I’ve also had moments where I’m watching a movie and look away at something else for a moment, and am briefly puzzled why I can’t understand it any more.
Subtitled 100%.
I don’t find reading words to be difficult at all. A dubbed live-action film takes me right out because the sounds I’m hearing don’t match their lips and it looks fake. I want to hear the actual actors act and hear their emotions.
I use subtitles regardless due to hearing loss, so subs for me.
I always use subs due to hearing loss. However, when watching anime, I use whatever will piss off the weeaboos most.