Oh, stop it Torger, that's simply not true.
Your 7D might have a problem, but across the board there are far, far more 5D Mk II users that have reported pattern noise "problems" than have 7D users.
Or perhaps yours is better? I'm not sure. I was under the impression that camera sensors don't really vary that much concerning these properties. I have only precise information about mine, and stuff I've seen on raw converter forums, both user and development. I would not be surprised if 5Dmk2 users report pattern noise issues more often, since those users are probably more picky about this issue and shoot ISO100 from tripod more often. I have both a 5Dmk2 and a 7D and have compared them. Note that this problem is most visible on ISO100, on high ISO photography you probably won't see it, if I remember correctly it is almost gone already at ISO200. I shoot 99% at base ISO though, which probably is a quite unusual use for a camera like the 7D.
If this is a problem or not depends on what you shoot of course. A lot of photography don't really need much dynamic range. In landscape and architecture one may however be forced to underexpose some to not clip highlights, and then later compress in post-processing before doing the print. In these cases 1-2 extra usable stops can be valuable. So I find pattern-free noise profiles to be an attractive feature of a sensor.
I think the 5D has a bit nicer noise profile, less of the corduroy pattern, a bit more of horizontal streaks though but the pattern is less obvious. I've attached an example from both 5D and 7D. The one to the left is 5Dmk2 and the one to the right is 7D. It is a 100% crop of a shadow area of a test scene which has been underexposed 4 stops (from precisely tuned ETTR exposure verified with RAW levels) and pushed back up 4 stops. 4 stops is a bit exaggerated of course, but I wanted to make it clearly visible. Shot at ISO100. The raw developer is RawTherapee without any noise reduction etc applied, this shows what is in the file.
