Having looked at both VisVSA and CETOL one of the things that implementors may want to consider is how your tool stores it's data. Does it have it's own data base? If so, how is the data associated with the production geometry which goes through many changes and then released (solid models). You may find that you will need to figure out how to manage yet another data base then figure out how to tie it to your Solid Model Revisions to reflect real world results.
Norm's points are good ones. Simply put, it's about cost avoidanace. Advanced packaging, Solid Modeling, Tolerance Analysis, CAE, Plant Layout, etc are all cost avoidance tools and is something which is difficult for most to understand.