John_ wrote:Ok why are you so loyal to CF cards ? Or need 2 different card types in one camera ?
In my case, it's because I have a couple dozen of them. And when I bought my wife a T2i, I wasn't happy that it took only SD cards.
I am not sure that is a good reason but it is a reason, I guess. CF cards are faster and they are more robust. Granted this difference has dimished in the last little bit of time but never the less it's there. They are easier to handle.
The two slots allow much more flexibility. Different file types or real time backups, etc. In a consumer camera this is not as important. But in a pro model it is essential.
And with a Canon pro camera you get both. So you do get the best of either format. SD or CD. 
John the term "crop sensor" is totally over used and misleading. The wonderful 7D and 7D Mk II show you exactly what you get in the view finder or LCD screen. To the vast majority of camera users the them, to them it is meaningless.
The only practical use is to give you a relationship of the focal length numbers on the lens compared to a 35mm film camera.
Some say it has a telephoto benefit. And some photographers make use of this in sports and birders, etc. Whether it is actually a benefit is up to debate. If it is there is also the same loss of wide viewing on the short side.
Most consider a 35mm lens as "normal" on a crop camera and a 50mm is more "normal" on a FF body. There again it is just numbers.
If you want a camera that is more "pro" in build and you want a speedy camera than the 7D series is for you. If you do like the look that you get from a FF, better low light ability, but are willing to take a lesser built and slower camera than the 6D is good.
Another benefit to the crop series of camera is less expensive lenses as it can use any lens Canon makes where the 6D can not.
Remember no camera does it all. There is no free lunch in photography. You give to get and you have choices.
