I know I dump on "Damage on a Miss" a lot here (and I always will) but for what it's worth: I really like the idea of Weapon Mastery.
I like the idea of fighters getting to do more than just stand in the same square and do the same thing every round. I like being able to do more than Just Damage every turn...knock swords out of my opponent's hand, splinter their shields, knock them back 10 feet, trade places with them on the battlefield, kick sand in their eyes and blind them for a moment, hamstring them so they can't move as quickly, deprive them of their reactions, keep them from healing...I could go on. I don't even mind wuxia-style, anime pseudo-magical effects straight out of Avatar: the Last Airbender, or DragonBall-Z, or Street Fighter. Fireball-slinging monks? Yes please. There's plenty of room in D&D for historic samurai and feudal knights, and mythological heroes of ancient Greece, and modern anime demon hunters with swords the size of ceiling joists.
Also, I think that keying these abilities to individual weapon types instead of to Feats or specific subclasses (looking at you, Battle Master!) is brilliant. Weapons in 5E are dull, and there's lots of room in there for growth. 3rd Edition had some pretty good ideas--some weapons gave you a bonus to attempt certain actions, for example--but they didn't carry over into 5E. It's a rich area for development, and dovetails nicely with the need for more interesting Fighters and Barbarians.
There's even a historic precedent for it, if you care about that sort of thing. I've used Weapon Mastery rules before, back when they were introduced in the Companion Rules set. They were quite different back then...so was everything else about the game...but I enjoyed them. Fighters and Dwarves really struggled to be interesting on the battlefield under the BECM rules, and the different weapon stunts really helped. (This was back when there were 7 classes in total, and three of them were actually "races." Talk about getting theme-locked!)
Anyway, I'm gonna leave the thread. I just wanted to clear the air, regarding my opinions on Weapon Mastery in general (love it) and "damage on a miss" in particular (hate it).