I see, doesn't somebody have exact measurements and weights,etc that can be used to make one handle just as well?
Yes and no. One of the aspects that seriously seems to have been lost (and yes, this derives directly from the lack of market, since swords just aren't used in today's market like they used to be), is the fact that a katana needs to be fitted to the user. In this day and age of weaponry that CAN be mass produced and used by anyone, we forget that, for a skilled swordsman, the blade needs to handle just right, and due to the immense differences in individual people, it's just not possible to have a sword that's right for everyone. It's a rare custom these days that builds a sword specifically for a customer. There's a particular stance in kendo that helps you identify the proper length for your sword, and depending on what kind of form you use, the sword dimensions may be different from person to person to optimize cutting. Depending on your arm length, torso length, leg length, etc, the same sword will be at different angles in the same move from person to person. Because the art of cutting with the Japanese sword is so integrally tied up with precise angles of cutting, that means that the same sword in different hands may cut very differently from one practitioner to the other.
There's not that much "drinking the mystical kool-aid," when you really get down to it. It's just a matter of the universal truth that skill matters. You wouldn't argue that some random high school soccer player is the equivalent of a Pele, or a Preki (dating myself here), etc, right? Or, for that matter, just check out the wide range of skill levels in knifemaking these days. I would be very cautious dismissing the skill and artistry represented in the cultural heritage of a swordsmith tradition passed down for generations as little more than mystical mumbo jumbo. To MOST katana buyers, there may not seem to be much difference between one sword and another. But then, most katana buyers swing a sword like a baseball bat, and don't even know how to grip the thing correctly, let alone how to actually use it with any kind of real proficiency, or how to choose blade length, curve geometry, tip geometry, weight and weight distribution, handle length, etc. (The only reason I know this is because I have a close friend who is a former world champion and knows many of the intricacies of the Japanese sword, btw; I'd be one of the average buyers otherwise).
Does all of this matter much in today's world? Not really. But for some of the really great pieces, there's a whole different level of quality beyond pretty much anything that gets produced today, outside of a custom from a swordsmith who really knows what he's doing, and how to build a sword for a particular customer. That's why it can cost thousands and thousands of dollars for one of those, when most of us would be satisfied with a good piece from a Paul Chen or a Chris Zhou, or a Cold Steel, etc. Incidentally, I would never personally buy a Cold Steel katana. They, in my opinion, are balanced way wrong and are far too heavy for the length, and handle like hogs in my hands. I do like most Cold Steel products, but their swords are not my cup of tea.