if I'm honest with myself I'd be hard pressed to think of an image that I've shot with my 5DIII that I couldn't have shot a year ago with the 7D.I have issues with your comparison.7D iso over 6400 anyone? I don't get that noise until I hit 25k on the 5D3. to each their own but my 5D3 and 7D images are night and day.
I think that's unfocused's point -- the 5D3 may be better, but maybe not for what he shoots or how he shoots it. What if he doesn't need ISO 6400, for instance?
Arias' only argument in that video that I'll back him up on: the limiting factor is usually our ability, camera know-how, composition skills, etc. and not our hardware.
That said, I do need ISO 6400 and I love my 5D3 for it.
Yes. Most of my photography falls into two categories. Things I shoot for myself for my own pleasure and personal expression and things I shoot for others. Not commercially, but generally as a favor to others who can't afford to pay (head shots for starving actors, senior pictures for kids whose families don't have a lot of money, family member portraits, etc.)
I seldom shoot over ISO 400 if I can avoid it, especially when I'm shooting for myself – which are the images I really care about. But, there have certainly been times when I have needed and appreciate the high ISO capabilities of the 5D3. But, few of those high ISO images are ever going to go in my portfolio, so what I was really referring to was the images that I am most proud of.
Just trying to bring a little perspective to things, I guess. I don't think Arias' point (nor mine) was that there is no difference between formats, but that the differences are not nearly as great as people make them out to be.