I was having this same discussion recently with a customer. I am a firm believer in that you are only as good as your equipment - to a point....
I have no doubt that given the same lake and conditions, KVD could outfish me with a Jon-boat and a combo from Wal-Mart with me using his boat and the best equipment money can buy (although would like to think he wouldn't out fish me by much....). But, given his skills and the best equipment out there, well, like he's doing (and done) he would be out fishing the best of the best. I say all of that to point out that using the same equipment as KVD will still not make you KVD as I am sure we are already aware.
The premium blanks are exceptionally lighter thereby increasing performance and sensitivity - weight is the enemy of performance. They are better made meaning they will last forever and be more reliable. Everyone jumped all over a certain "high-modulous high performance" $100 rod a few years ago. After all, a "high performance" marketed and labeled rod for ~$100 is hard to beat.
But, the bottom line is this: there is a reason a rod costs a $100 - period. This is now being proven out as you are now hearing more and more about the $100 "high-modulous high performance" rods snapping like dried twigs. The way the "high performance high modulus rods" are done is that blank mfgrs DECREASE the graphite and added more resins thereby reducing the weight and increasing the "modulus" which lowers the costs due to less graphite.
Less weight, higher "modulous" and less costs - great for marketing but not so good for serious fisherman! Reducing the graphite reduces the overall tensile strength of the blank which is just as, or, more important than modulus. The tensile strength is what allows the rod to deform (bend) without breaking. The ~$100 "performance" rods under extreme conditions deform but the fibers fracture and break because they do not have the tensile strength support due to shortcuts or inferior materials during manufacture: less graphite, inferior scrim, etc.
Now, as a custom rod builder, I say all of this to point out that upper-end rods like the St. Croix SCV's, NFC, Phenix, etc. all use lots of graphite with a premium scrim - fiberglass, high-quality paper or in NFC's case another layer of woven graphite. High modulus and high tensile (Strain) materials are what make a high-end rod truly high-end. Like Pappa John says: better ingredients make better pizzas. Same is true for fishing rods and the costs are typically reflective of the quality. Yes, the premium blanks and components are that much better. Period. I say that without hesitation or question. Will the additional cost catch more fish? Well, that's up to the person with the rod in their hand. I believe it will. If nothing else the confidence of knowing that you have the best equipment available to you makes a big difference.
The choice is ultimately up to you, the consumer, if it is worth it.