I'm still on the fence, deciding which car to buy and those are currently my top 2.
The GS350 gets approx 300 hp out of a normal V6 engine.
The 535i gets approx 300 hp out of a twin turbo V6
Advantage Lexus... the lexus engine gets better mileage, is likely to be cheaper to maintain, and the BMW if there first turbo in 20+ years, so who knows how it will go.
The BMW is more athletic to drive. The stability features and suspension in the GS350 make it kess aggresive (although it's just as fast as the BMW). Both are available in a AWD. The BMW downgrades to a 5 speed when you buy the AWD.
The exterior and interior styling is completely subjective, but I prefer the BMW interior, and the GS350 exterior.
The GS350 has a more intuitive touch screen based interface. But it has horrible restrictions on what features you can use while moving, and has limited customization. The BMW i-drive does more, has better customization, but is uglier, and less intuitive. The BMW gives you much more detailed status info about the cars systems (oil level, break wear, etc...).
The BMW has traffic in it's nav, the GS350 does not. The Lexus has rear parking camera, and front/rear parking sensors, the BMW only has sensors (no camera). The BMW has a cool heads up display option.
The BMW has a much larger trunk. The lexus has better cup holders.
The premium stereo in the Lexus is better than the BMW. The BMW has a better ipod and USB adaptor than the Lexus.
On average Lexus dealers are much more appreciative of your business and easier to work with.
The BMW includes 4 years routine maint in it's price. The BMW is going to be more $$$$. The Lexus is going to be more depreciated since you are currently buying a 2007 Lexus vs. a 2008 BMW.
