Beg to differ
Let's face it. The main reason you ( or many people ) think X3 is bad, is because it doesn't look "flashy" or "Qi4 Pai4" as X5. Just admit it, dont find other reasons you dont really know.
As a matter of fact, for a long time ( before the current X5 ), X3 actually had BIGGER interior than X5. If comparing the same engine, X3 3.0 handled/drove much better than the X5 3.0, cause the same engine is so much inadequate in X5.
X5 3.0 just doesnt make any sense, to showing off is the main reason for those choosing it. Ofcourse, V8 powered X5 is a different story.
X3 is actually quite popular in Europe, and the latest X3 3.0 is earned Canadian SUV of the year I believe.
Again, the only problem with X3 is that it doesnt look "flashy" at all. Otherwise, it combines driving fun and practical so well.