My 5d2 was one of the early ones, early adopter here, back when. You know, swayed by the fanboy enthusiasm when it first arrived.
The noise mine produced was more obvious to me than your example but pattern noise is there in your example too. I can see it even on my everyday machine with my low end Dell display.
... just have to look a bit closer for it.
Here, I've popped it up a bit to make it easier for you to see it.
I just took a crop from the upper left of your crop so no cloud fragments, enlarged it 4x and did a quick de-sat and contrast kick with Preview to make the patterning more obvious.
Can you NOW see all the stripey vertical noise and pixel non-uniformity?
I don't want that kind of junk in
my i mages. I find it visible on-screen and in moderate (12-18") size prints.
Others may not notice it, most don't, but I see it and I'm the one who needs to be satisfied with my images.
So no, it's not as clean as from ABC, sorry. Even MFT with it's extra shot noise has less or no pattern issues.
Those old Canons were rife with pattern noise. Whether from multi-channel read noise issues or pixel non-uniformity as I've learned from Bill Claff's articles on his website. Net result is the same.
My 5d2 had channel read noise issues AND significant non-uniformity issues as a picket fence right across the middle third of the sensor. Yup, sure would have returned it if I'd have figured it out in time.
My 5d2 -
most disappointing camera I ever owned.
I shouldn't have listened to the raving fanboys back then.