Top lane is even worse. Please bring Rengar top vs. Darius or Jayce if you are on the enemy team.
I never said he wasn't bad in top lane (in fact, I said he was overall bad), just that he's kind of fun in lane. Far more than his iffy jungle, anyway, for a fun playstyle. As far as lane is concerned, it is really easy to counter him but he does dismantle basically everything outside his counter picks. Unfortunately, his counter picks are basically "Everyone good at top." Still, leaping from bush and surprise bursting someone is kind of fun. Even if that is his entire gimmick.
That said, I've only lost lane with Rengar something around four or five times total so far. Darius twice, a Teemo, a Fiora, and probably someone I'm forgetting. And all of these were jungle assisted and not straight losses. My bigger issue with him isn't his laning phase but his late game without good initiation from the jungler/mid. Winning top is pretty easy for the most part.
...of course, outplaying at the elo range I'm playing in (unranked, at that) isn't really an accomplishment.