Sure, you can use R3Ds for straight-ahead live-action projects with minimal effects, but I agree 100% with what Bruce says above. I think for a real workflow where time is of the essence, and you have to conform, color-correct, and output material with limitations on time and budget, DPX is a wise choice. In the real world, you'll still have lots and lots of range to work with in terms of color and exposure.
The reference to Dragon Tattoo is very apt. That workflow obviously worked very effectively, and proved that there are many ways to get to the finish line. From my perspective, too many people are getting wrapped up with theoretical methods and not considering the most direct, cost-effective approach. I have no problem with keeping everything 4K all the way, provided you have a very fast pipeline, tons of storage, and a considerable budget. In the real world, if you have a small film with a modest distributor that's mostly going to be seen on Blu-ray, download, and cable, I'm not sure it's going to be practical for indie filmmakers. Big studio projects, no problem.
And I still have many issues with long-term archival storage. But that's another topic.