It seems that you have been drinking the same stuff that yellowsaddle drinks
you know all the answers.
I suggest you first read Dura Ace 7900 specs. I'm not one that takes these guidelines too seriously but in this case I know from experience. It's the pull ratio that is different but the difference makes a brilliant set of brakes into very poor set of brakes if not combined with 7900 levers. So much that Shimano went back on its design for the 9000 series.
The difference on calipers is not just materials and weight, maybe that is the case for same manufacturer, ie 105 and ultegra. Design is also an important difference between manufacturers. I've seen enough Tektro brakes to know they aren't at the same level as Shimano brakes. The other component that comes to mind that the difference is not just weight and material is QR Skewers where Shimano make the best skewers I know. I'm sure you will disagree with that too