[Greenbuilding] metal-faced foam sandwich roof panels -- advantages?

[Reuben Deumling]

I was just offered a large quantity of 4" thick x 42" wide x 20'-30'
foam-metal sandwich panels that look as if they had been intended for use in
roof insulation. They are faced with metal on both sides, one side having a
textured surface that looks like it would be intended for the exterior. They
feature a fancy groove pattern for joining sheets together. I was imagining
using them as an exterior layer on a house roof, but although the price is
decent, their size (and weight?) is real impediment. Have any of you
encountered, used, or liked them? Is their large size (fewer seams) and
integral roof surface worth the extra trouble of handling and storing them?
The roof in question to which I'm considering adding them has only two short
hips and one (planned) dormer.

I think this link might describe the product or something similar
http://www.pu.bayer.com/db/pu/pu_cms_internet.nsf/id/7D8A9ED8D468D571C1256F6B00420A4D

Thanks for any advice..

Reuben Deumling