I debated for almost 2 months between the '07 Lexus IS-250 and IS-350 and BMW 3- Series. I was mainly looking for an edgy style and most important AWD for the snow in the Northeast. The IS-250 is nicely appointed but pricey when adding options (low power). BMW is nicely appointed but 328XI AWD does not compare to features of MB C280- 4M. It's nicely designed for '07 (a colleague told me about the MB low quality of past years) and I'm particularly finicky, which is why I even considered an Avalon and VW Passat. But for the total package of Options, Power, Luxury feel and sturdy (or luxury drive if you choose) along with Sirius Sat/Nav and Ipod Integration, there is no comparison in price.
4-Matic AWD. Luxury Features, sturdy feeling drive and believe it or not, the power of 225 horses is not bad at all. The gears shift very smoothly and you can also play with tiptronic/manual shift for a more sporty feel. The look (in and out) is very sharp and attracted me (and I'm very picky).
More leg room in back and headroom in front. Better NAV system (touchscreen would help). MB and BMW have overly complex and very crude (low graphics) NAV systems. Too much manual effort (wherease Japanese have user-friendly, more sophisticated and voice controlled NAV/Audio/Climate Controls.