Pendleton Butter Stub review

I've been happily using an old school TWSBI 540 for about two years now.  This isn't any ordinary TWSBI, though.  This one is armed with an "Elegant Butter Line Stub" nib (hereafter referred to as "BLS"), created by the nibmeister Pendleton Brown.  The BLS nib started its life as a steel TWSBI nib, size B, I can't remember if it was a "Bock" or a "Jowo", nor do I much care for such distinctions, since I'm mostly concerned with function.  And since being transformed by Pendleton Brown, the TWSBI /BLS oozes function.

2012 era TWSBI 540, originally with Broad nib, but
now with a  Pendleton Brown Butter Line Stub