Hello Mixedup,
FYI...
AT&T has a similar 4 line, 10 cordless handset system with PTT available now. It is made by VTech.
It is AT&T SB67118. I am testing four of these systems now and they are working pretty darn good.
Repeater units are available to extend the range and coverage has not been an issue with us.
The system does not have an external music on hold input but I understand this will be changed in the near future.
Regards, DT98
