Please allow me to offer my comment on this subject.
Forget about brand name, just compare the two car, I was going to buy CX5 Diesel but cancel my order and choose to drive a Volvo V60.
The issue with CX5, as correctly pointed out by Volvo USA CEO, "it drives without the feel of power" is disappointing. Yes, Mazda can claim how great their ACTV-D technology is, but ultimately, this is a strange diesel engine. Typically, in turbo diesel engine, you get a flat top torque curve at low rpm, in the case of my V60, it starts at 1500rpm. From that point all the way to 3500rpm, the torque is at maximum and stay there. Therefore, you can build up speed quickly with a diesel at low rpm. CX5 is different. The car has two turbo - one small and one big - that looks great but in reality, the max torque starts at 2000 or 2200rpm (sorry I forgot) but the torque curve beyond that is not flat! It actually drops! So when you drive CX5, at low speed, you get a very quiet SUV with sufficient torque but nothing to be excited. As you further depressed the accelerator, pumping beyond the 2000rpm mark, you get a dip in torque and then building up again as higher rpm. At that point, noise and vibration all kick in loudly and very rough. This is not something people familiar with diesel will be expecting. Certainly the noise level was unbearable and that is one reason I cancel my order, after waiting for three months!
I have not driven the Sant Fe but I expect based on ix35, the performance of the torque is similiar to the main stream diesel engine. Frankly speaking, at roughly the same price, I believe Santa Fe is a better choice but it is Korean, so I can understand the feeling.
On the subject of MIJ vs MIT (Local assembled), I really do not feel there is a difference. The assembly quality on my previous Mazda 6 2009 was horrible. Poor alignment of parts, noise from the door and seat, suspension etc The quality of material was great, far bettern than any Taiwan assembled car. My point is, in today's term, where it is assembled is lesser of an issue than what material is choosed. Taiwan assembled car uses too many local parts, that are not as good of a quality as the Japan made car. I am not afraid if my volvo is assembled in future in China, as long as the qualification of parts remains in the Swedish hand. That is what matters.