100%...one pixel in image is mapped to one pixel on monitor, so if you have a 1280x1024 monitor you view a 1280x1024 section of the image, regardless if the original image was 3072x2048 (10D) or 5616 x 3744 (5DII). It is an absurd magnification equivalent, same as viewing about 43 x 65" (45X) print image from 5DII from 10-20" away, or a 68X print from an 7D APS-C sensor!
IQ from a dSLR is a combination of LENS and sensor, and you are viewing what the lens can deliver to the sensor, which is not terrific at that magnification.
What counts is what you see when the ink hits the paper!
Print More, Peep Less ! <------ good Bumper Sticker!
Pixel Peeping just doesn't make sense.
Maybe we can provide help to the Pixel Peepers? Create 12 step program for the addiction, and create a support group and call it PPA. ( Pixel Peepers Anonymous )