Well, Paul was actually onto it before me so the credit goes to him ;-)
As for the Windows thing, Mach3 really does amazing things with Windows. When Art started doing Master5 (what is now Mach3) it was said to be impossible to get 8kHz from the LPT-port under Windows - which was what he aimed for at that time. He did it and the "world" was astouned, the rest is history.
If you really can get 150kHz out of EMC2 reliably that's quite impressive and if it does what you want then by all means use it. And no, I have no personal interest in either one of the softwares ;-)