Douglas Dean. There have been a number of occasions at Wersi concerts and demonstrations that the keyboards have locked-up (Wersi use WinXP OS) To reboot the board can take several minutes leaving an embarrassed player waiting on stage.
You state you have had no problems with your MAC. The reason is the MAC OS is very good and stable.
Spend some time with a Microsoft OS PC, then you will see the reason players do not want a MS Windows based keyboard.
I have good knowledge of PC's after many years of putting problems right (Still learning every day) I would never buy a board built around MS Windows.

Graham