I bought a 4.8is a few months ago and it has been a great car with absolutely bags of power. I've had BMWs for 20 years now and this is the best one I've had.In the past I've had Alpinas (4.6 b10v8 and a C2 2.7) 540 estate,a couple of shark nosed 635s and a few 3 series. They cost a bit more than your average X5 to buy but I'm sure it would be worth it-happy hunting!