I've written about this several times, if briefly (not here, I've just given this thought).

If you're reading fansubs, you're absolutely right that there can be too much information. It's a blessing to read the proper definition of a word, or find out that "boy's day" is a real Japanese holiday. It's a curse because the screen *really* starts to require attention.

Since most standard (non-fan) subs don't include all that info, it's seldom been an issue for me. The subbing included in most decent productions are much more natural, and can be effortless to follow. I can also read fast, so that helps.

Still, I do wonder when I know a foreign word in a language and then don't see it written down (or its possible slang use). I think meaning may get lost sometimes because some things aren't actually translated.

If you know Spanish, you know how often things get left out. It must be a billion times worse in Japanese. Apparently, the actual translations of some episodes titles are, basically, poetic...

There's a big problem (with subs) that you missed though: when they're not timed right, subs can mess up a moment. You find out the end of a sentence, and its important info/impact, while people are still at the beginning of the sentence! It could kinda kill the climax of a powerful reveal, or the rhythm of a scene.

For my part, matching mouths never mattered. It's more important for the mouth of a drawn character to be expressive, right? I'm used to it enough with foreign movies, and I require even less from anime, I guess...

I do greatly prefer subs. Still, I don't like being stuck to the screen, either, as you and Darth Katie stressed. And now that I've dropped all anime except for Miyazaki stuff, I'll be straight up and admit: I loved Howl's Moving Castle, and I haven't watched it in Japanese yet.

It was really easy to love, since Disney actually ponied up for solid actors (bale, driver, crystal). Also, the movie is amazing - I'd love it in Swedish with no subs, probably. I think I heard that Disney also asked Miyazaki to include a few extra lines to explain things. I don't necessarily like that too much, but they got the writer to do it himself, so I can't really complain.

I agree that it comes down to the right cast. I loved Ranma in both English and Japanese, but I ended up following it in English because the actors were a blast. Then later on, I find out Inuyasha is on AdultSwim and it's horrific because everyone sounds freakishly bored. Also, all the terribly-pronounced Japanese names are painful to the ear every time.

I wish it was all available with quality subbing and dubbing. By and large, I'd stick with the subs. It would be nice, though, if I could switch to English when I want to get a bag of popcorn from the kitchen. It's cool being able to do that with foreign live-action films...