There is no difference in output between running central with an XM or a GX.
Both generators can generate the frequency range of plasma which is 100,000 Hz to 3 MHz (3.5 MHz for some).
The XM is capable of up to 5 MHz without using wave cycle multipliers.
The major difference between the two generators is how well the generator can resist plasma energy as an interference source.
The XM is more prone to allowing interference to lock the USB communications up when compared with GX. The GX Pro currently locks up a lot more than either of the two.
However, many of us, including myself, ran Central with an XM long before the GX was even a reality.
For more details, please check the link: