Joe,
Joseph has designed an excellent preamp with a great topology at a specific price point. But even with the best-designed preamp circuit topology, it is only as good as its parts can give you, hence the desire to upgrade to premium parts. But these premium parts usually come with a price, so that is why Joseph gives certain upgrades to help those who are set with a certain budget. I believe that this new Claritycap MR line is an advancement of capacitor technology, and it is relatively new to the market and as a result, since Joseph's evalution, he will soon place it into one of his upgrade packages. Victor also mentioned that Joseph is currently experimenting with some premium resistors that will further improve the presence and aliveness of the sound of the preamp. "Good things come to those who wait." ( my mother used to tell us this, but I never did understand it. (O:)