Do 1D4 images "crop better" than 1.6x cameras?

When a 1D4 image is cropped, does it retain better IQ than a cropped image from a 1.6x camera (7D, 60D, 50D, etc) ? Assuming both images have about the same amount of cropping.

I've read that cropping a 7D image causes the noise to become more apparent, or more of a problem, than those of the cropped 1D4 images.

I don't own either camera, but if true, then it's something to consider for those who plan on doing a lot of cropping (sport shooters, for example).