It is simmilar to the Siemens vs AB topic. In europe mostly all PLC's are supplied by siemens, while in North America AB is king. But for SCADA this is even a bigger "issue" the main SCADA is still WinCC, and if there is one platform that I despise as non OEM, than I nominate Siemens...
But hey, at least we are considering expanding the Ignition platform in Hungary (Europe)