hi,
I had to face a very similar situation a few weeks ago.
It was either an X3 (2007) or a 328xi. Both had plenty of power for me, the X3 being quicker. The 328xi has a more compliant ride, and a better interior. (look, parts, quality). The X3 was , higher off the ground, slightly faster, and had a bigger trunk, but at the expense of a harsher ride and a less than stellar interior.
Good Luck.

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T