It's overly dramatic, but in a weird way that's part of the appeal, like Gurren Lagaan's insane energy.
As for subbed or dubbed, well, I would go with what way you think you'll enjoy it more. I watched it on AS, and can say it's a fairly good dub, but it could have been better.
I like Lelouch's more teenagery sound in the dub than how deep he is in the japanese, but on the other hand the deepness of the japanese seiyuu really works well when Lelouch is in Zero mode. I like Suzaku's tone a bit better in english than in Japanese. And I love Ogi in english. But alot of the side characters like Kallen, Chigusa (can't remember her actual Britanian name), and Shirley are not as good as in the Japanese version. And I really don't like Nunnally's english voice.
So, I guess go with what you want. Personally, I think it's generally better to check it out in the original language first. If you have the DVDs, you can just switch back and forth if you get curious about what it sounds like in the other language.