I haven't seen Yas get banned or played, anymore at all really. He doesn't seem as strong as he was before, although he can still snowball, however, most other champions can snowball in the same way. And I haven't had a Yasuo been a problem in such a way that he's able to pick off more than one person in a teamfight. Which, I mean, he's an assassin and should be able to do that, if nothing else. I've been playing a lot of ADC recently, and haven't had a problem with Yas'. Even when I was playing Mid, especially with someone immobile like Xerath (146,180 champ points on him), I didn't have a problem dealing with him middle. And, I'm not sure what you mean by hyper tilt potential? Lee+Yas together is a really tilty combo if they do it right, but the champions separately aren't usually a big problem. Unless they get snowballed, which most champions can be if they're snowballed (Like I said before).
I feel his fun factor doesn't come from the "easy" ults off teammates knock up, which there are few and far between that are guaranteed ones (non-skillshots in my head). Off the top of my head, Lee Sin and Vi come to mind. Maokai too, I think, with his Q, possibly. Also Blitzcrank. But, it comes from the fact that he can just keep dashing and dashing and dashing. Like, it can't stop, won't stop. And the windwall is kind of fun, when you do it at the right moment, like cutting a blitzcrank grab in half.
In my last 20 games, I've had 1 Yasuo in a normal, and he had Yasuo in his summoner name, so it wasn't that surprising.
