Originally Posted by Palmnuts
...much as I really loved the C63 and the sound of it, the M3 is still the one I chose to buy again last summer and that because its the only car, except my current XKR, that I could't really fault at all(manual 'box aside in my first M3, rectified by the fab DCT box in the second one).
The M3 won't sound as thunderous as the Merc, it's certainly not as well built (you're definitely signing up to more rattles in the M3), the seats and driving position are a million miles behind and it's less exclusive (the Merc is still relatively rare compared to the M3). The M3 is also slower....not massively so, but slower nonetheless and theres nothing an M3 can do to lose the Merc on the queens highway hence I've always held the Merc in higher regard as a road car.
Yet I find myself now noticing a glimpse of that datenesss in the Merc, the M3 induction noise is nearly as good as the AMG's exhaust (but is enjoyed less often on the road), the M3 really does handle a lot better unless you spend zillions changing the C63 like I did, the DCT gearbox is the best 'box ever, the latest iDrive is the best comms interface I've seen.
In summary, the Merc blows you away at first but you tire of it sooner. On this basis, I fully understand how a 1-2 day test drive would tempt you into the AMG. The M3 is less special initially but has a deeper talent to keep you entertained for longer and as I've said before, the only car in the last 6 years that I've kept for longer than 12 months (my first M3 that was).
If you've definitely narrowed it down to these two then buy the M3 and buy it in that colour. But make sure you get a HUGE chunk of money off it....just remember, I bought my M3 in the summer for about £15k less than list - OK, it was a demo but unless you get something approaching that discount, it's going to drop worrying amounts of cash very quickly.
Just joshing, never drove either so I know jack, I'd just be happy to afford the petrol...