Where's your bottleneck?
I shot on a 7D for the first 2 years of my career. It said 1080, but it wasn't 1080. It wasn't really even 720. Then I got and hacked a gh2. My footage was so much sharper. But the dynamic range still wasn't there, and clients still had a hard time respecting a tiny DSLR. So I got the C300 at 0% financing. It totally paid for itself. My footage was even sharper, a true 1080, and with a good 12 stops of dynamic range. Worth it in every way for me.
Now, I had the benefit of working for 2 years with the 7D. I did everything I could to get it to look as good as it could. After those 2 years, the camera was the bottleneck. When I started out, I was the bottleneck. A better camera would've been wasted on me. I needed to learn to light.
That said, there's no reason to get a 5D when you can get a C100 for the same price. The C100 is so much better for cinema it's not even funny. Now, I have a Red Dragon and a C300, and if clients didn't still ask for the C300 specifically, I'd swap it out for a C100.
Great list, but I’m not sure about #7. Let’s say you’re directing and your DP says “I’m going to do his and you’ll thank me later.” So you say “I hear you, but I want it this way. Do it or you’re fired.” Now you’ve just totally screwed yourself. Either they don’t back down and you have to fire them, thereby costing production days at best, or they do and they hate you and phone it in for the rest of the shoot. I’d love to hear other peoples’ thoughts on this, b/c the only solution I can think of is to not hire someone like that in the first place. Reminds me of a story about Coppola and Willis in (I think) The Godfather. They got into a violent shouting match and turned to Michael Chapman (the Camera op) to settle the issue. He ran to the bathroom and locked himself in the stall till they figured it out on their own. (A damn smart move!)