CCDs are a big reason why nikon had been behind canon for so many years. They are much noisier in longer exposure or higher ISOs. They're used in cheaper cameras but SLRs deserve something better.
I think there were large noticeable differences between the two...up until this year (so that doesn't necessarily help you)
Also....Nikon's CCDs are actually Sonys. That's enough to send me running.
For me, the last word is always DPReview's side-by-side comparison tests. And that exact test is here:
Nikon D40X Review: 23. Compared to...: Digital Photography Review
....and honestly in the first time in the history of dslrs, the two really are neck and neck. So nitpick your own choice, and know you made a good decision either way.
