dookiebob said:
The S4 is much more of a driver's car than the 330ci is, IMO. ... and the suspension is firm, but relatively compliant.
I can't believe I just read this....god bless the internet and differing opinions!!!
Now, my brother own's a 330Ci and I was shopping for S4's a while back, so I have driven the two hard back to back.
Without a doubt, the 330Ci with a sport package murders the S4 in every way in the area of handling (unless it's snowing

) as far as feeling is concerned - who laps faster...I haven't tested, but my butt dyno tells me the 3-series is the winner. The S4 really does feel numb and mushy - it doesn't communicate to the driver. When you are in the BMW, you feel connected to the road.
The clutch take up is terrible on the S4 - again, numb and dead to the touch. The 3's clutch is far more positive feeling and it's way closer to the floor then your typical VW/Audi clutch is (something I like). When I first started with the BMW...I HATED the clutch..now I love it...it's totally different then any other car I've driven...and different from the E36. The brakes...it's the same thing....one is numb...the other...near perfect.
The engines are two TOTALLY different animals. While the bi-turbo is a torque monster, it doesn't touch the silky, turbine-smooth feeling of the I-6 in the BMW. Not only do you have to worry about blowing the turbos, you also have to worry about warm up, and more importantly cool down after driving the car. Now of course you need to do the same on the warm up side with a NA car, but I'm not comfortable with leaving my car running with a turbo timer.
As far as the interior is concerned....I kinda do like the Audi - and it's soley b/c it's a better car audo car - it has a more symmetric dash, room for a double din (although you can get one in the bimmer) and plenty of room under the dash and in the kick panels. The down side is that the spare tire well is WORTHLESS for audio. IT also has a larger 120A alternator, but BMW thinks ahead and puts the battery in the trunk. I dont' think that you care about the above features, but I figure I would throw them in there. The Audi is also more roomy up front then the BMW, easier to get into as well. As far as comfort, I have not had that much experience with the Audi....I think it has an edge aesthetically.
Both stealerships are AWEFUL in my area, so that's a wash IMO. One note on mods though....while it's cheaper to get gains with the Audi, when they go...they go BIG!!! Some time over at audiworld.com (great place btw) and you will see what I mean. I'm sure Dinan will release the supercharger for the E46 soon...when they do you have a warrantied car that is still servicable at your local dealer...to me that's a pretty big advantage for the Bavarian.
As far as the exterior looks....it depends on the day...Brad, your Audi looks great, and when I first came here, your car fueled my drive for the S...but I also love the BMW...again they got the ride height, etc just perfect from the factory.
Here's my 0.02 - if you want the ultimate driving machine, a nice sport coupe that does everything very well, and performs seamlessly....go get the BMW. If you want more of a touring machine that can be a total beast, a sleeper if you will, that you can take to the snow....and if child seats are anywhere in the near future, then the Audi is the clear choice.
I was drawn to the S4 b/c of the modding potential and the Quattro. One look at the dyno for APR stage 1, 2, and 3 is enough to wet any gear head's appetite. And it's plain beautiful from all angles.
After extensive research (and experience in the BMW) I still feel that the BMW is the better all around car. IMO, the S4 requires at least coilovers to be in the same league as the BMW straight from the factory.
One is a sniper rifle, the other is a shotgun....depends if you want brute force or scapel like precision...
In no way do I think you can go wrong though...(btw, I am/was in the same dilemma, and I think I'm going with the '99 M3 - I really feel that car feels "perfect" in every way) The only way I'd buy the Audi is with an AA extended warranty....they are just way to expensive to fix otherwise.
Sorry that was so long...just wanted to throw in a somewhat unbiased, opinion considering I've done extensive research and have been behind the wheel of both.
Hope that helps...