Changing over to canon soon. Besides the basics, I'm not familiar with all the very technical aspects of cameras, will someone please explain what the differences are between the 7D and the 5D mark ii ? In the side-by-side comparison on Canon's website they appear nearly identical with the exception of the metering mode. Almost all of my work is portrait and I'm considering picking up a couple of weddings in 2013. I may also buy a used camera so I can put more $ towards lenses.... would anyone recommend doing so/not doing so? Thanks for all your help!