I've been seeing one or two in nearly every match, and I just first-timed him on my main (after a brief session in Practice Tool) and clobbered my opponent while handily outperforming my teammates (NB: I am trash). I'm pretty sure I used a bad keystone for him, too (Aftershock). I think he's strong.
He has a lot of reach for a melee champion, and he thrives on AoE situations while also being able to force a 1v1 when necessary. This makes him really hard to stop even as a team if he gets a lead. He seems to scale well, too.
That said, he has trouble with champs that also revolve around reach and sustain, like Karma. Her E helps her avoid his skillshots, she can poke with Q, and RW is a good tool for surviving his ult. I tried it yesterday on another smurf and, while I gained absolutely no lead on him, he couldn't do anything, either. He must've been really bored by the time he abandoned the lane and started roaming. However, he then proceeded to get pretty fed off of the rest of my team. He ended 14/7 but didn't get enough of an early lead to pull off a win. I can't go into much more detail than that because Match History is broken for some matches and refuses to render anything but the Statistics tab.