You know what? I watched the test clip on VirtualDub (uncompressed) and it was good; then, after you pointed out the faces looked waxy, I took a look at the compressed file, and indeed it looks awful... at the end, it was the high compression that gave that s***ty look! And I thought X264 @4000kbps could be good enough...

I just tested few seconds at 16000kbps, and it's just another story; it looks like almost as good as the uncompressed version... so, I'm encoding it right now, and it will be ready in less than an hour - bigger file, but more quality this time, I promise!