I tested the 350 and there was no comparison in road feedback. Also, 335i felt much faster to me. I don't trust any of those drag time results. I remember edmunds got a 5.6 0-60 on that car and 13.9 1/4 time. (see the photo/video section at http://www.edmunds.com/new/2007/lexu...landing.html#)
Those times were confirmed by my personal experience. There is no chance that car is as fast as a 335i, not even close. But the kicker is that vision out the rear of the IS350 from the driver seat sucks ass, especially compared to the 335i.