If and when such things were to become available.

THE BMW IS NOT BEST IN ANY CATEGORY EXCEPT MAYBE HANDLING, but nobody could see handling.

That's pretty much my assessment. However, the BMW 3er is a good compromise. Not the best at anything, but near the top on everything.

Looks are subjective, but I think the 3er comes in second to the X-Type with the rest of the pack behind.

"Luxury" could need a bit more definition. If this is feature content, BMW is up there near the top if you are willing to pay for all the options. If it is just ambience, then again the 3er is second to Jaguar but near the top.

Acceleration goes to the Acura & Infiniti as you noted, but BMW is well ahead of the rest.

This makes the 3er still a good choice if you want it all. Unfortunately, while not so long ago it was the no compromise choice, today there is no such thing as a no compromise choice.

If I had to buy in this segment, I think the decision between an X-Type 3.0, a 330i or a G35 would come down to who offered me the best deal. That's not "lowest price" - Infiniti would win that. Rather more like best offer for my trade combined with the most off of MSRP. I think I could be satisfied with any of the three, but would have some regrets with any of the three.

I also thing Jaguar is currently in the best position to take the "no compromise" brass ring. It's easier to add HP than to restyle the interior (much less the exterior). Add enough horsies to be as fast as the Infiniti G35 and I think the X-Type would be there.

Horse power could be easily added cheap via aftermarket parts. K&N air filter, swapping the chip of the car could easily add up to 30hp for less than $500.

I can understand where an air filter might add a few HP to the car and maybe a little more MPG, but what chip is going to add 30 HP? I need more clarification on that claim. Whazzup?

The K&N filter is good for 2-3% in HP, and the Chip would recalibrate the engine management computer with a nominal increase are anywhere from 5-10% HP. Wheeee!

K&N filter are already available, and the Chip should be availabe also if not soon. I'm not sure of the exact increase in the #, but Bob numbers are probably not too far off.