Anecdotally, TOP once had a post that is similar to this thread:
The Online Photographer: How Come Nikon Beats Canon So Badly?
A post on that thread tells a similar story to mine here,
The Online Photographer: How Come Nikon Beats Canon So Badly?
In my case, I don't think Nikon is "fiddly," but I otherwise mostly agree with the poster.
Nikon (Sony) sensitivity is definitely better. Nikon (Sony) resolution (especially the D800) is definitely better, especially for landscapes. Nikon bodies are, IMO, better. These things count and Nikon takes all of these points. But none of this matters to me if I feel like another camera would take a better picture under the circumstances.
I've only tried the D90, D7000, and D600. I couldn't love any of these cameras. Maybe the D700/D3/D4 bodies would fare better.
With respect to PP, I feel like I have to "work" a Nikon file to make it look good. And after I've worked it I often still don't like it. But Canon looks good SOOC and even better after PP, and doesn't often lead me to dead-end photos. When I see all the B&W Nikon photos I chuckle and tell myself that I've been there before, and I don't want to go back. (Yes, some B&W is an artistic expression, but B&W is definitely there for wonky light that cannot be corrected, too).
I don't believe that Canon has more faithful colors, and I'm pretty sure Canon can occasionally smear texture even without provocation (especially in the red channels), but I forgive these errors because I like the look of the pictures (especially in the reds and yellows). If texture is the price I have to pay to get nice colors, then I'm willing to pay that price. I also prefer Nikon's bodies, ergos, pop-up flashes, DR, sensitivity, etc. But I don't feel short changed buying Canon.
To my eyes, Canon images are warmer, have better reds, yellows, and greens, and look more pleasing as an idealized moment that I want to remember. To my eyes, Nikon reds are weird, greens are weird, oversaturated colors in general, although detail retention and sensitivity are very strong. But I'd rather have a grainy picture with good skintones than a sharp picture with bad skintones.
I regularly use the HSL sliders in LR4 to adjust an image to my taste. I know that settings can be tweaked. Despite this, I believe that Canon is doing something else with their images to make people look better. For example, Canon could be reducing contrast strictly in the red channel (similar to a red filter on B&W). I wouldn't be able to see the tweak in a final image and I wouldn't know that such a change was made, but I would know that skin would generally look better. Another example might be using a warmer WB, but also moving the black point toward blue to cool the shadows, bringing balance to an image that would otherwise look too warm. This is the type of stuff I occasionally do with both Nikon and Canon files, though I work it harder on Nikon to get what I want and often don't need any such tweaking on Canon.
I think that Canon processes images better and that LR4 is tuned better for Canon. I don't need to know why or how. I know that isn't satisfying, it doesn't satisfy me, either.