....Recently I had a few photos with a somewhat dark sky where it literally looks like it is raining because of the vertical noise bands in the more solid areas of the sky.
Send your unprocessed cr2 files and your camera to Canon and get it fixed. I have the same body and I have never had a dark sky 'literally look like it is raining'. You say it is 'recent' and 'a few photos', so get it looked at.
I've been trying to just "push on" with my 7D... but the continued poor IQ out of my camera and the prices on everything Canon releases going up... and then the announcement of the 6D (which doesn't fit what I'm looking for) all adds up to me selling my gear and moving to Nikon.
You mean Sony type N. Given your emphasis on sensor performance, that's the new name for Nikon. (Wouldn't it be neat if Sony took over Nikon and produced two camera ranges, the
alpha and the
nu?)
I hope that people who stick with Canon end up getting what they want eventually... I would love to wait but I can't deal with what's coming out of my camera right now...
Most Canon users are getting what they want NOW, thank you. Some Canon, Leica, Sigma, Pentax, Olympus, Sony and Sony type N users are not getting what they want; it's a generic disease.
P.S. if your objection to a 5D III is
price, jumping to Nikon makes no sense given their pricier and optically inferior lens range. You will lose out in dollars (and in imaging results (sensor + lens) if you are a chronic pixel peeper, although I maintain excellent and satisfying photos are available from any of the major brands).