Crikey some more BM bashing no there's a surprise on ASN ?!?
Back to the original question, I have both cars, my wife now uses the 335d coupe on a daily basis and I use it whenever it takes my fancy or if attending a BMW track day, both cars are remapped with slight handling mods.
The 335 was actually remapped by Evolve who are a cracking company offering decent products and a well reputed RR, the S3 runs GIAC software etc.
It's a very difficult question to answer without timing gear as the cars produce there power in different ways, the 335d is an absolute animal with amazing shove but is also very well refined so it can be decieving until you glance at the speedo. On wet roads the S3 would be the weapon of chioce but thats not to say there is any issue whatsoever with the E92's handling, it is safe and very predictable and the balance and steering feel excellent, on a dry day I don't believe you would be getting past the 335d and I'd hasten to add the 335d driver would be having more fun. I'm not knocking the S3 they are just very different cars if I was not fortunate enough to have both cars in the family and had to choose only one I'm pretty confident I'd choose the 335d as it has so much presence and just looks and feels like a car from the class above, sorry if offended but just my opinion.
350bhp, over 500lb of torque continually available from 1700rpm to 5,000, 39 mpg - 0-60 5.3 secs, great figures in comparison to the S3 the only real negative for me was the lack of a manual gearbox which I greatly prefer.
On the subject of interiors how many of you guys that have expressed a negative opinion have actually spent any length of time ina 3 series coupe with lthr etc ? The Audi has the edge for tactile materials but the layout in the coupe if spot on, quality not an issue and no rattles, squeaks or problems in 12 months/20,000 miles to date.
Open your eyes Guys there are loads of good offerings from other brands.