Continuation
I don't like the BMW X5 and wont be buying one, but the car (like all cars) has some good points, and I don't think the RX400h will beat it in all areas.
Taking your X5 comparison to the Rx400h I'm not sure all your numbers stack up, but I'm not going to do an advert BMW to disprove your point here.
The extra fuel ecconomy of the RX400h is marginal. Just £200 pa for a car doing 10k miles per year. Even in the unlikely event of you doing all 10,000 miles in the city you would still only save £500 pa. Big deal - not.
Regarding faster, we all know that it's not the 0-62 time that matters but how it's delivered in normal driving situations. Most people would'nt notice the difference between the two in everyday driving. If LexusJohn's comments on power deliver are confirmed, it's points to the X5.
Regarding less expensive, most peoiple see beyond the sticker price. Based on your prices and What Car residuals of 65% for the RX300 and 70% for the X5 you would lose 18 grand on the Lexus vs 14 grand on the BMW.
Re your question do you have a problem? Answer quite possibly. This isn't leapfrog, but it might be catch-up?