Actually, the old V8 (M62?) had a wicked, American hotrod exhaust note, that you could hear two blocks away, even at low rpms. As much as I don't like muscle cars, I couldn't resist that note in the E53.

The E70 I've driven had the 4.8 N62 V8, which is very smooth and seems to have better top-end punch. But I dunno, it was missing excitement, although it was fairly quick and IMO, the only proper choice for an X5.