In the case that the functionality not is in XSI Foundation it's probably not in the more expensive packages either as there actually are very few things has been removed from Foundation. You will however also find stuff in XSI that you wont find in AM. AM is a greate product. My reason for leaving it was that I got into the second category in that quote. However, as the upgrades have used to be $99 from any version I'm quite sure that if I get some time over at some point I might order an upgrade just to se what's happend since last. I have allways had that kind of love and hate relationship with it;)