Is he into it for the storylines, or the animation ?
Appleseed is rather disjointed in its delivery when mixed with English dubbing. Likewise many Japanes animation falls flat owing to limited budgets on content, even though the stroyline could have delivered so much more.
I would invest in a HD ready TV, and maybe a HD player/streamer, just in case your nephew is more akin to the technical detail than the story. Or get him a voucher for the Japanese section of your local content provider. At 12 though, he will have a hard time getting the better films of the top shelf