I have it equipped on my Cap, the dmg proc helps in WBU tremendously and he's a beast in TL with it. I always time the proc on his t3 skill and he scores almost 2 million in ABX, I'm on lvl 37 of Proxima atm thanks to him, he's also great against Corvus with ignore dodge leadership/strikers
I'm thinking of giving that to him too ( whenever I have one lol.) But i never have damage proc on him, so I'm not sure how easy to time it. From my experience though, Caps with CTPD kill my defensive JG just only with his 5.