The 14n at 400 vs the 1ds, thats a shoot off I would love to do. My 1ds at 400 is way toooo noisy. Many others have reported the same. Whats so interesting is that unlike Kodak, Canon has done nothing i.e. firmware to help out. They just choose to deny the issue exists, sounds like many others.
The 1ds pulls way too much noise in the red channel which is unlike others that tend to pull the noise in the blue channel. If you shoot an outdoor scenic with a deep blue sky and want a nice dark blue to the sky, be prepared for the noise and lot of it. Often times I need 400 to pull a faster shutter speed to stop the motion of trees and such and with the 1ds its a major issue.
The cleanest camera I ever used at 400 was my old S2, amazingly clean even at 800, but it had its own image issues.
Where I know the 1ds will hands down outpreform the 14n is on longer exposures. I realize that a newer firmware is coming to help out on this issue and so far Kodak as delivered on everything so far.
My one big issue with the 14n is simple, only on raw converter supports it, photodesk. I like having more than one option as you do with the 1ds, (Canon, Adobe, Capture One, maybe Bibble someday. )
Paul Caldwell