First of all, the main reasons for buying an suv is cargo space combined with awd (we have the driveway from hell in the winter). and station wagons are a disgrace to the 5 series imo.
second, lexus's are NOT cheaply made cars. We've owned two and they've never had any problems. They have THE BEST reliability of any car company i've ever heard of. including bmw.
ps: the rx300 has an even lower center of gravity than the x5 and their brand new VSC system. no, they dont flip. i own one.