It's something about the brand's power in that country.
I'm working as a commisioning engineer in Turkey; siemens owns more than half percent of the market, modicon telemecanique and ab follows em.
The end system users, purchasing managers etc. dont care about the flexibility, or scan times, or AI's, or communication protocols... They just care about having a "SIEMENS" branded system here.
I entered the sector with ab, used almost ewery cpu, hmi, driver and scada applications. AB's products are (both software and cards) user-friendly, easy to operate and manage.
Siemens is more sophisticated, user-enemy!, but i can politely say STL,DB and FB based programming is more powerful than AB's ladder.
I think u should add a third brand, modicon telemecanique. They are rising in the europe sector for being the 2nd brand. I dont know the american market (except ab's power), or if u ewer heard of em.
These are news from Turkey and Europe.... Take care!