While the X5 at first seems a little pricey it's standard features make the price much easier to swallow. Xenon headlights, normally about $800 on some BMWs are standard as is a 205 watt sound system with 12 speakers including 2 sub-woofers. Also standard is an alarm system that cost as much as $500 on an X3. Add the fact that all X5s come with BMW's great ZF (German made) automatic transmission rather than the GM6 (French made) transmission found in the X3 and you've pretty much talked yourself into paying a little more. I'll admit that the mileage won't be quite as good as the X3 but the ride is wonderful with only a little roughness noted over the most bumpy of roads.
Smooth as silk automatic transmission coupled with that BMW inline 6 engine that they are known for. Panoramic roof.
I know the diesels are coming for 2009 and I'm sure they will be as good as those available in Europe and most of the world.