I just wanted to post a few pics to clarify the difference in cooking temperatures. The roast I cooked and reverse-seared below was cooked initially at 225*:
You can clearly see that the pinkness extends all the way to the edge of the roast. The one below was cooked by Ron_l at 275*:
You can see that the outer edges are cooked a bit more than the center. Note also that he does not perform a reverse sear, but just does a slow roast the entire time. Here is one cooked by Boshizzle at 325*;
The outer cap is well done now and the inner portion is medium rare. Note also that every roast shown is absolutely delicious!
There are three points to this:
1. Different cooking temperatures will give you a different product. The higher the temperature, the greater the doneness gradient in the meat. This is true for everything you cook. It is why we cook smaller pieces of meat at higher temperatures than large pieces.
2. There is no "right way" as all of them taste absolutely delicious!
3. Rib roast is easy. How many things can you vary the cooking temperature by 100* (or more) and still have a great product?