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suggests that the CLK will be new for for 2003 and based on the current C-Class. The arguments over which vehicle is technically better should probably give way to which vehicle you like better.
If you want to get info on the CLK in general, I recommend the MBWorld.org Forums site:
(If this doesn't work, try the address up to "org" and navigate from there.) The guys on this board are somewhat fanatical about their cars, but if you ask questions there, you will get many useful answers.
By the way, the BMW 330Ci is more directly competitive with the CLK 320 coupe, not the CLK 430, which is a V8. However, the CLK 320 coupe will still run about 4K or 5K more than the 330Ci for a similarly equipped car.