re: BMW vs Lexus vs Mercedes vs Acura vs Infiniti vs Audi for four door sedan

I own both. Specifically an is f (v8) 416 hp and also a full bolt on and tuned BMW 335i. I have owned two is350s (2007 and 2010). I know the product. An m3 (what the isf was built to compete against) is faster than the is f. It just is. I went with the F because I didn't want m3 problems. BMW performs but they have way more problems. A Lexus will run forever. I like both brands for different reasons.