I've settle down on Leonardt Ef Principal nib. It's the best nib for my needs and the many inks I use.
I've tried some brause nib with "natural" ink, but they don't like it.
I've rubbed and cleaned them with toothpaste and what not and it doesn't matter. They only like sumi inks.

I wonder has anyone used Standardgraph drawing nibs for calligraphy?

What is your experience and do you have a favorite?