There have been several questions on these filters, so here is an updated post that I originally made on the X10 Forum:
In case anyone is interested, here is a frequency sweep showing the response of the XTB-F10 and the X10 Pro XPF. The sweep is linear from 20KHz to 220KHz, with 120KHz (the X10 frequency) at the center.
The top sweep is the simulated powerline noise at 2V per cm. The lower two traces show the noise that passed through the XTB-F10 and XPF at 200mV per cm. A resistor was inserted in series with each filter to prevent loading down my signal generator and causing interaction between the two filters. (Without the resistor, the peaks on the XPF are much larger as that series-resonant circuit sucks energy from the signal generator.)
The XTB-F15 performs similarly against powerline noise, but it isn't quite as good at isolating "signal suckers" as the F10 due to its lower value inductors.