If Wikipedia is to be believed both variants were introduced at the same time by the same company (Key Tronic). The European one fits one key more. I never had

If Wikipedia is to be believed both variants were introduced at the same time by the same company (Key Tronic). The European one fits one key more. I never had problems to hit the European-style return-key for what it's worth and need a long time to adjust to the US variant whenever I have use them.