Either way, when people talk about "Katana Wank" they aren't talking about, or at least I hope not, "It's possible that using a katana with a Feat that lets you use it one-handed might be slightly mechanically superior, or might not, then a longsword. Maybe. The math is complicated."
Definitely not me. I was referring to the mythological attributed awarded to the katana in fiction, the ideas that it was physically superior to Western weapons and would slice right through them or shatter them, that it was so sharp that it would bisect steel and that a hair dropped on one would part under its own weight. Basically the idea that the Secret Arts of the Mystic East
made weapons far beyond what grunting Westerners could manage.
My experience with D&D katanas was rooted in the
1st Edition AD&D, with
Oriental Adventures, where the katana was a one-handed weapon that did 1d10/1d12 damage to small-medium/large opponents, as opposed to the longsword (which in that rulebook included blades such as the Japanese
tachi, the Chinese
jian, and so on) which did 1d8/1d12. It was a minor statistical advantage, but the big deal was the samurai class feature that treated their family sword as magical weapons of increasing power as the character leveled up (the point being that a samurai's
daisho was supposed to be treated as part of their honor, and not set aside because they'd looted a spiffy +3
frost brand tachi off some oni they'd killed*).
*Pause for snickering about Susanoo-no-Mikoto, the original
Dark Souls player cutting dragon tails for new weapons**.
**Additional pause for "Eureka!" forehead-slapping moment to realize that probably
actually is the origin of being able to cut off dragon tails for weapons in
Dark Souls.