Nowadays, more and more devices use phase width modulation (pwm) power switching, for example motor inverters, and induction cookers. The frequency they use is 20-30Khz. Switching devices generate noise in multiples of the basic switching frequency. Narrow band PLC lower than 500Khz might be affected. This is something to be concerned with. Generally, CENELEC band (<100khz) is more noisy and FCC band (150-480khz) is preferred for those applications -- to provide more distance between the harmonics of the pwm noise and the narrowband PLC signaling. Maxim has not run tests to quantify the difference. However, one advantage the MAX79356 has is you can use the same part and firmware for different bands and you can switch the bands as needed.