I may go ahead with 5d3 on this one, but I have made a promise to myself that I am going to test out the medium formats personally in the near future and judge for myself.
For the life of me I cant figure out why so many of you are saying there will not be an IQ difference on a coffee table book if shot on a 35mm 23mp camera vs a larger 60mp sensor....
Must get to the bottom of this!
I'd say this is an excellent idea.
The 5D3 is more than capable of delivering professional results with knowledgeable operation and an eye for composition. I believe a great image is made when you know how to use the tools at your disposal. Some of my favorite images were made with a 7D, and those 18MP look great even on a 24x36 canvas.
80MP images aren't necessarily better...only larger. You still have to know how to use the tools to match your creative vision. I'd much rather have a beautiful 23MP image than poor 80MP!
One final note on the 80MP: files that size are most helpful in areas like fashion photography when you're cropping into an image and need to maintain a high resulting resolution.