Some clarification. I install many headers of all types and brands. Perhaps the most important single factor for my shop is what I call 'fitment', or how the pipe fits. The most difficult, by far, has been the Muzzy and Yoshimura. More often than not the pipes hit somewhere. They generally smack into the oil filter, radiator, oil pan, frame, etc. Usually I am able to make some sort of modification, short of cutting, welding, of some other nasty modification. More often than not when servicing a bike, I find that the header is smashed against something. The owner never has a clue.
I used the Micron only as an example of a header that has yet to present any sort of problem on any application. From time to time I also have to replace the muffler packing. With the Muzzy or the Yosh, the end cap's stainless steel rivets must be drilled out first and re-riveted, while all the Micron canisters have a clever removal system. There are many other top quality systems out there as well, but the Muzzy and Yosh aren't among them.
As with so many other products, the most popular and readily available has little to do with a product’s actual value. Often times the best items are downright rare and relatively unknown. We are often motivated by marketing (as in Harley Davidson) and not by quality, engineering, or any other meaningful factor. It’s very easy to fall into this trap.