I'm not sure on the 35i but my 3.0SD (LCI equivalent 35D) has 600Nm of torque and to my understanding the Porsche has 550Nm, obviously the Porsche has more HP but I was pleasantly surprised how much of a difference torque makes, my M5 has 520Nm and the X5 pulls like a b*tch I mean that thing goes, fast. IMO Porsche has the better name and has more prestige but the BMW looks better, I would personally go for the M sport just because I couldn't bear the plastic on the SE model but that's my preference. My nephew used to have a Cayenne Diesel (No comparison to the Cayenne S) and it felt really well put together, the only thing I didn't like was horrid design of the centre console, it's too cluttered and messy, again that's my preference. If it was my money I would go for a 35D M sport with your selected options, the Diesel has more power than Mexico, unless unleaded is your thing then the 35i would still be a good choice. I just personally don't like the front of the Porsche or the interior although it does feel a little better I still think the X5's feels better thought out and more ergonomic, you might get used to the Porsche with ownership but I found it a bit of a pain.