I would take the C-Class, because the Mercedes feeling suits me better than the over-reacting and too sensitive steering at high speed of the Beemer. And I find the C-Class much more attractive designwise.

All the reports say that the C-Class is a bit less sporty (feeling, not numbers here) but much more comfortable, and thus offers a better mix between comfort and sport.
Of course if you like the Beemers, you don't really want a balanced mix, but a car that is more spory than comfortable (without becoming a Lotus), so you go for the Beemer.

To each his own. But everybody has to reckon that the W204 has become a real threaten to the Beemer.

Concerning the sales, I only saw that the C-Class outsells both 3-Series and A4 in Germany at the moment and that Mercedes sells more than they thought.

That is just the launch of the car so let's wait sometimes before saying it is a flop or that it has already lost the battle, ok?

I've driven both E90 and new C-class. Both works for active driving and for relaxing drive. Both fine vechicles but here in Sweden 335i is cheaper than a C350 and 335i has the power advantage so it would be my choice. C-class is a very good allrounder but so is E90 so once again it comes down to personal preferences.

PS My facelifted 1-serie is very stable on the road. Just put on the cruise control at 140km/h and you drive the car with no drama at all. No nervosity at all, I love it.

PS i know 3-series had some problems at high speed when it was introduced but the fault was on the runflats. Runflats has been improved during the years but still they are no replacement for "normal" tires..M- cars dont use runflats, thank god for that.

Has anyone else noticed that AMS always seems able to meet BMW's official 0-100 times while the results for benzes are usually slower, sometimes over 1 second slower?

are you speaking of swedish AMS or the german?
German AMS always get slower times than other german carmags, it least when they test BMW and many other brands.

This is because they don't want to burn tyres, it is not environment-friendly...

They don't stupidly put the pedal to the metal, but make a green 0-100 time. It is a kind of hybrid-acceleration time, you see?

German AMS, if you do a quick search for AMS on the forum you will find a lot of test scans where BMWs perform within 0.1s of their official figures while benzes usually lag up to 1 sec behind. In this particular Swedish AMS review, C280 was 0.3s off vs 0.2s for the 330i

I tend to look beyond 100km/h, there the real differences are. Particulary 0-200km/h times.

Is it really that important to have 0.2sec more or less to go to 100km/h?

It depends on the temperature (cold mean poor traction for the tyres), are the tyres cold or on temperature, is the car new or already at its highest performance level, was it good used or not whereas the first 1500 kms, the reaction time of the driver, how fast he changes gears, the type and size of the tyres and wheels (big wheel means slower acceleration, large tyre mean better traction)...

Acceleration times are not so precise, just give you an idea of the performance of the car. It even can change from one car to another, even the same model, due to fabrication margin and how the car is used.

I was merely pointing out that German AMS consistently meet BMW's figures and consistently fail to meet Benz's. True that test conditions affect performance but they usually stay the same throughout the entire test where the cars also remain in the hands of the same drivers.

I also used to believe in manufacturing margins till a few drag races in identical cars (of different makes and models) proved me wrong. All other things equal, identical cars performed exactly the same, like they were tied together. Seems at this day and age manufacturing processes have eliminated those margins.

You want to say that AMS would be BM-biased? I don't think so, I sometimes read it, and sometime BM win, sometimes Mercedes...
I never give attention to acceleration times; 3 reasons:

1) I really really don't care
2) My Golf will outperforms every tested cars
3) If not, my fabulous driver skill allows me to win everytime;

last time I even passed a Citroën 2cv on a road. He could do nothing I was faster.