I really love Gillian Anderson and thinks it's cool she made a voice for a Miyazaki movie. However, I also prefer to watch the original versions, and the Swedish dubs for example, are just horrendous.
What should I do?
Alternate. You're not forced to pick just one for the rest of your life.
Let's be bad guys.
The English dub for this is fantastic, so watch that.
One major difference in plot between sub and dub comes from Lady Eboshi (Minnie Driver's character) after the threat is averted...she comes to two very different conclusions about how to proceed with her ironworks, depending on which version you watch. It' interesting. The English dub's take on it is more honest and realistic (if depressing), whereas the subbed/original has it more idealistic and "lesson learned"-happy ending-ish.