Wow, I hear a huge improvement in the Japanese model: the difference between a robot in person and a young woman on the phone.
Listen to the samples here for example: http://voicetext.jp/samplevoice/
I like the sound of Risa in http://voicetext.jp better. Try it out the Japanese Google used in their example. If someone knows of a better one it would be great to find out.
一つのウエーブネットのみで、多数の事なら、話者の音声波形極めて正確モデルができます。