I've already done it. Works fine for me.
Maybe you got lucky and selected a clean 7D, they do exist.
Run of the mill ones aren't so good.
But also, lets' not see a high contrast B&W shot which can reduce the effect of (primarily) red channel noise. I use B&W to hide a noisy shot too.
Lucky you. So what's your answer to the question in topic?
My answer is to buy what works and my advice to Canon is to develop better sensor tech on their own or license it from the competition. And start supplying it to us FAST!
I'd love to be able to use my Canon glass and bodies instead of carrying a "mixed bag" of gear but I've been disappointed by banding noise on all of my Canon bodies since I went digital with a 40D. At the time it was a hair better than the comparable but upscale D300. 40D is still my preferred camera in some ways but I quickly discovered its limits and have been repeatedly disappointed with low ISO performance of every subsequent Canon body I've bought since (about 15 of them).
Biggest letdowns were my 5D2 and 7D. For that kind of money, those cameras should not have more banding than a darn Rebel or a compact like the G11 or G12. They're no longer image quality leaders at the low ISO end of the spectrum.
I was just about to spring for some T&S glass from Canon but now I'm hesitant. Those lenses on the 5D would compose some stuff for me just how I want it. But when I crank the file I won't be happy with the results, and, after seeing what my D800 and D5100 can do, I really can't bring myself to drop nearly $5k on a pair of lenses only to be compromised by mediocre sensor performance. I want either Canon to improve their bodies or Nikon (or some 3rd party) to make better wide T&S glass.
Fortunately I might be able to afford to hold off dumping much of my Canon kit for a while and see what happens over the next year.
As an alternate gripe, I still find myself, let's say 'amused,' at those whose opinion of DxOmark's results are disparaging to DxO or the Nikon cameras which attained the high marks they doubt.
Some of us are actually using camera systems from both manufacturers, and pushing the raw files to their limits at times to create the images we want. The differences noted by DxOmark ARE REAL and they CAN show up in everyday shooting. It seems many people don't know where to look for the flaws or don't care if they see them.
When these same image files are pushed the difference becomes quickly apparent which sensor technology is superior for low ISO dynamic range.
I don't shoot weddings, nightclubs or motorsports after sunset, so high ISO performance, as impressive as its recent improvements in the 5D3 and 1Dx may be, are only one side of the argument.
Many of us shoot in SUNLIGHT. Harsh, contrasty and uncontrollable for all but intimate settings. Under these circumstances, the extremes of shadow and light are captured, compressed and presented as a final image far better, IMO, by sensors in recent Nikon cameras than by sensors in any Canon DSLR.
As such, Canon has an option to listen to the complaints of consumers of their products. Should they try to satisfy these demands for better low ISO performance, their engineering branch is going to have to work very hard to catch up to the competition in this aspect.
Call or email Canon and let them know your opinion on this if it matters enough.