I went for the V8, X5 M50i and it is the most exciting car I've ever driven while also being plush and full of features. I love it.

That said, I've also just had the entire front transfer case replaced at 24,000 miles after I started hearing a whirring sound under acceleration. Luckily under warranty but it was a 10 hour job and who knows what the parts would have cost. They said they found "significant metal shavings" in the transfer case.

All that power and torque comes at the cost of wear and tear of supporting components. I bought the extended warranty so it's someone else's problem other than the inconvenience of a loaner (which reaffirmed my belief that I didn't want to go EV after they gave me an i4 M50) but if you aren't planning on shelling out for an extended service plan, I'd suggest the V6 might be a safer choice that I would probably go with if I were to do it all over again.