Need a favor from the 7D owners. Bring up a very underexposed image (or part of an image) in ACR and crank the exposure 4.5 stops or more until you can see the noise pattern in the recovered detail. On my 7D, it's striped as in the first pic below. The second pic is the same type of thing (different image obviously) from my T1i. Note how the T1i noise is fairly random while the 7D noise is definitely striped. Is this normal or is this an issue with the 7D sensor?
7D
T1i