MGX21 is for a different riding style just from seeing the MGX21 in person and the pics of the Concept 101.
In the US, I doubt if the prices are within a few thousand that buyers would choose the MG over the BMW. The MGX21 has a more locomotive look to it. Chances are though, that the BMW is going to cost quite a bit more than the MG.
I did like the riding position of the MCX21 though, it seemed very comfortable but more for short rides, not something for longer hauls.