Yeah the diesel market has yet to catch up some momentum in the US, here in U.K the 2L 520d 5 series is the most likable/preferred model, the reason being it's the cheapest, cost comparatively less to run than the more powerful siblings and also cheaper road tax and insurance premiums plus all multinationals give their managers/employees bmw 520d as company car. It is a hot cake really, in the same way as toyota. corolla is in Pakistan 
The 535D m sports are a beast really, with about 280horses under the hood and if you get them remapped, they can get to like 350.