I can't really cast a vote for somebody else's decision as, IMO, it depends on the driver. My wife and I would vote BMW, but that's just *us* and most of our friends would be happier with the Lexus. NO question the Lexus would be a more trouble-free ownership experience, but I think he'd just have to drive them all and then make his decision.
If he doesn't appreciate the higher abilities of the BMW, then the Lexus would be a no-brainer choice. If he finds the Lexus' limits during his test drive (heh heh, imagine face of Lexus salesman
) then he'll want the Bimmer and there won't be any question in his mind about the choice.
*MOST* people really just want a good appliance that gets them around, so I'd bet on his taking the Lexus.