The Marmitek unit appears to be no more than a bridge between a wired network (home LAN) connection and the CM15Pro (or other RF transceiver) relying on the CM15Pro for macros, etc. And, if there's a WiFi router in the network, it would allow for communication with any WiFi enabled device that is allowed a network connection. But, it appears to be one-way, sending X10 RF but getting no feedback from the X10 system.
Based on the limited information we've seen so far, the new unit from Authinx appears to be more robust - perhaps eliminating the need for a CM15A.
However, if Marmitek has followed recent X10 designs, it may use third party RF transmitter/receiver modules. If so, adapting it for N. America would merely require replacing the RF modules and the power supply (or maybe just the power cord).