Hopefully someone will come along who has a clue but that sounds strange. I can't relate directly because I only have the default V3 SAE without all the head morphs but in general it sounds like I get better performance with a much older (1GHz Athlon), lower memory system. The lags you're getting just seem odd to me. Do you have the last P4 patch installed? Also, I didn't see a mention of how much memory you have. There is, I believe, A patch for P4 running on systems with (I think) 2GB+ memory. Other than that, I don't know, something just sounds funky.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken