Coming from someone who has had both audis and bmws, they are both good in their own right. I love my 335 and think it is easily one of the greatest values out (performance, quality, or otherwise). That being said, I still preferred the interior of my audi and the quattro was awesome. When comparing the s4 to the 335, it is important to understand that they are very different cars. The 335 is a new motor with superior fuel efficiency and technology while audi's 4.2 is already 5 years old. Even though the 335 is moddable, etc. the s4 has one of the greatest exhaust notes (IMO of course) and the brute force and responsiveness that comes with an NA motor. Both are great cars in their own ways. People need to realize that it is less important to stack one car up against another comparing 1/10ths of seconds and go with what they prefer. My advice would be to drive both cars and see what best suits your likes/needs.

 

Like most, I considered both cars before buying a 335i. The things I didn't like about the Audi were:

1. The gas mileage (21 mpg highway) is just really stupid. Although you don't buy these for good mileage, there are plenty of V8 cars around (ex. Corvette) that get great mileage from a V8

2. The gearing is just bad engineering. Any car that has you running 3,400 rpms at highway cruising speed (75 mph) is poorly designed. This is a recipe for short drivetrain lifespans

3. They depreciate horribly

4. The "black" interior bits (dashboard, etc) are really gray in color, it was bizarre

5. The bolsters wear poorly.....more than 1 car I looked at needed new bolsters....very C5 Corvette-like

6. Idrive does a better job of integrating all the electronics....and the stereo is better

7. Finally, the S4 handled like a boat, very soft and indistinct.

 

Now that the S4 has been out for a little while and the 335(x)i has been out for a while it's a little bit of a fairer comparison, as most of us assumed.

Though I am sure the hardcore enthusiasts on both sides would never consider switching to the other carmaker's product, I find myself in a situation where due to location I am reconsidering the 335xi.

Anyone in here owned or has test driven both the B8 S4 and the current 335xi?