I testdrove a black C63 a while back and made the following observations compared to the E55:

-The C63 has an excellent driving feel to it, I have to say its very different from the other AMG cars I ve driven, the E55 feels like a small tanker compared to it. Definate improvement here
-Love the looks of the car (S-class aggressiveness), I think they have finally cracked the styling (or am I getting older?)
-I love the sound of the car
-The manual paddles are very Playstation-like and I liked that
-The new NAV screen is nice
-The rear seats fold as standard (finally)

Negatives:
-I got exactly the same acceleration figures than from my E55, although the C63 feels faster, the E55 is just so calm about the acceleration. Its just that you feel is something happening and you see all other cars far behind you.
-Im sure to miss the Panorama roof and especially AIRMATIC suspension, I dont understand why you cant get this suspension option? It would be needed because of the crappy roads here. The suspension is really hard.
-The back seats are smaller and the car looks smaller than the E although I believe there is only 7cm difference.

All and all I was very surprised that I am at all thinking of the C. I hated the looks of the C55, but for the first time I am really thinking should I or should I not leap to the C-klasse atleast for a while? Am I really crazy just because of the fact that the C is newer or have they really cracked it this time with the C? What do you think, I am afraid that the new w212 E63 is going to look odd with the twin headlamps...

 

I went from the C55 to an E63. Went and checked out th C63 recently. Glad im in the E If you drive by yourself all the time then the C wont be too bad, unless you are over 6'3" the E is more accomodating for taller peepz as well as the large back seat.
I would personally mod up your E if you havent done it and stay in it.
Everyone was all up in arms origioonally when the C was only in Spy photos about how they didnt like how it looked, blah blah blah. I would guess the same would be true for the new E, should be an even more pimped out version of what it came from, hopefully. And would ulitmatly look better then the C when it finially comes out and will come stock with 100+ more HP. Also if you wait it wont look like you have to take a financial step backwards with you cars to your neighbors
I have only had my E about 15 months. I will probably wait til the E50TT goes into its second year of production before I consider my next move.
Good luck with your decision.

 

I've always liked the look of C63 AMG more than E92 M3 until my friend showed up at my house with the surprise.
New M3 is stunning in every way especially in white.
The interior improved alot(I love the new steering wheel+fit and finish)
I drove it and the car handles like a champ! Only took it up to 3500rpm since
it's in break-in process.
After dealing with car with lot of horses and torque, i came to the conclusion that it's no fun without good handling.
I read many articles on C63 about how handling improved compared to old ones, but i know for sure it's not gonna have the handling feeling of the new M3. Even every magazine stated that M3 has faster lap times and better handling. The car is just so balanced for that amount of weight. Plus M3 is more fun to drive with 6 speed manual.
Also the sound of that thing!!!again, i only took it up to 3500 rpm
I know C63 AMG is faster in a straight line, but im gonna give it to M3 this time. It's simply an amazing car in every way.

 

Had two other C-class AMG cars before switching to the E55. I actually had the #1 order on the C63 in Seattle but cancelled it shortly after taking ownership of the E. While I liked the outside styling of the C63, I hated the interior with a capital H. It looked really cheap and I'm not a fan of the pop-up NAV screen.

The E55 is just so much more sophisticated an automobile. I like the ride (even though the handling can't compare) and all the tech features (my E55 is loaded). I also needed more room than the C-class offers and I especially like the wider body and not feeling like I'm sitting up against the passenger. The bigger backseat for kids was likewise very nice. The E is very quiet (especially in congestion) and I really appreciate being more isolated from the road/traffic noise.

I'm sure the C63 is an awesome car but I have never looked back on my decision. The E is just a big step up in sophistication and luxury and I guess I'm at the point in my life where I really appreciate that (as long as it still goes like stink, of course). I'm definitely considering the new E (W212) AMG when it goes on sale. So far I'm not impressed with the styling so I reserve the option to instead pick up a pre-owned S65 when the time comes.

 

Well after having so many issues with my E63 for the last 10 months with drivability problems I was considering working out a deal to trade the E for the C63. I drove the C63 and yeah its fast but the interior looks too cheap for me plus the lease was rather high. I didnt like the ride quality the M3 rode much better and had better steering and control

I drove the new M3 and it was so much more fun. In NYC region you cant use 500+ hp cars to blast in a stright line thats why i rather have a better handling car to me its more enjoyable.

I have a M3 drop top with DCT coming in the summer and I picked up a 2008 M5 in the meantime as well all for obvious reasons.

 

If I were in the market now, I would choose the C63 over the E63...... I don't really care about the options, I just want a fast everyday luxury car....

 

I like the C63... alot! I also like the new M3 just as much... I'm keeping my E55 but I'm having a hard time between the two (C63 vs. M3) Right now, the C63 is a notch ahead in my book especailly if I can order the AMG Performance option, but the M3 is right there on its tail... Don't this white C63 look sharp?!!

(pic corrected from CLK63 to C63 now... sorry)

OR

 

I don't think that's a C63

 

Oops, I attached the wrong pic (that was my friend's CLK63 Black Series)
Here is the C63 - which they also just bought!!! I think they're changing the bumper lens marker to smoked or clear.

 

That's hot I love the white