Brian,
I'll agree that the X10Pro site has some very good information on the new units (as well as improved installation info).
Unfortunately, they do not include information on how to properly interface these new modules to the CM15a/AHP (the Pro site still handles the CM11a). When the Pro site starts handling the Cm15a we may begin to have good documentation on how to properly interface these new modules.
Until then, It appears that it is up to "we" forum members.
Boiler