Your comment: "it has been determined that Herceptin works best on people who test out at Her2+++ (which by the definition above are true Her2+ people). That may be where the 30% rate comes in to play, because they have found by giving Herceptin to those who are Her2+ & Her2++ generally does not work"

I cannot say about the 30% because I do not know what percent of Her2 overexpressers are even ON herceptin. I understood it to be a success rate number, but not sure how it was arrived at.
Can a link to the study be provided???

Agree with the idea that herceptin does not work as well with her-2 ++ tumors, but does have some effect. This is something the statisticians will have to sort out as more data is available. It may be that some of the other Her-2 women have hormone positive as well to deal with and it could be THESE tumors that become tougher to deal with.
I do know that in my case my med onc said that having a high grade +++ tumor (hormone neg) was bad enough and he wants me to stay on herceptin monotherapy as long as possible (damn the expense!). It is possible that when a new tumor sneaks in it is because it is so aggressive that the herceptin can't keep up with it. That is what a friend with a new bone met led me to believe. Now in combo with navelbine she is conquering the latest met nicely, giving the herceptin an ally in her fight.