Ok let's give this another try (and this time I'll save my comment before hitting "post"!). Actually I ended up watching the whole thing after you posted this, and I have to say I really fell in love with Goku. He can't have been much younger than the other actors, right? But despite that he still brought across all of Goku's childishness and excitement, I thought that was great. I really loved Hakkai too, that guy was just perfect for the part. Even without understanding anything, the way he talked seemed just very Hakkai-like to me.

But you're right, a Gojyo grin or really any kind of lighter moment would have been nice. I mean I loved all the angst and drama, but what's Saiyuki without the fun? Maybe that just got lost in the non-existant translation. But overall, I really liked it.