To your first point, it's not implied... it's stated on their website as well as in emails sent from them. As I stated upthread, my wife has also received the invitations directly from the TSA/CBP (forget which) because she is GE. She is a DL and AA zero.

Re the kids... it all depends and I don't want to get into a pro/con kids discussion. But my kids fly almost monthly and we always use the "expert" lane in ATL. However, my kids aren't anything on anyone because the flights are almost all short hops from ATL-MCO/TPA/DCA on DL credited to AS due to the occasional AA, etc., do MIA. Both my wife and I pack light with limited carry on, etc., and my kids know what to do. We're faster than many "expert" travelers who are carrying a full set of luggage and a laptop through the checkpoint.