1DMkII versus 1DMkIV - Pixels? Can I See The Differences?

I won't get into the particulars, but I have an option to add a 1DMkIV to the stable alongside the 1DMkII I already have for what is effectively way dirt cheap...but still pretty hard on my budget. I'm looking for excuses to justify the cost. I do a fair bit of of cropping, so picture for picture, should I be able to tell the pixel count difference between the two cameras? As we know, the MkIV has about about twice the MkII's pixels.

If you mean will you be able to crop more aggressively, yes.

Crop 'em both 50% and then print them 20x30...

You'll have a "Eureka!" moment.

I went from a 1D2 to a 1D4 and do crop a bit more now, mostly because of the limited reach of my longest lens. I would say you can crop at least 25% more and retain more pixels with the 1D4.

Almost double the pixels. I hope you can see the difference especially if you crop.