I just appreciate both. Like people have said, different models for different purposes. I love my 335i, as its more exciting to drive than my girlfriend's CLK350. But doesn't mean her car is worse, just geared towards a different type of driver.
Our neighbor's C63 AMG on the other hand... Wow
In the end, they're both great, and the brand competition will simply mean we will keep getting better and badder cars in the end.