I stand by twitch.

He smells of win.

Why is he a good choice for top?

...for the same reasons that teemo is a good solo top, and more. He counters tanky dps champs with his DoT abilities, he outputs more damage then most traditional solo tops, he has enough cc to get away in a 1v1 fight, plus his ult allows him to continue to attack his enemy from an extremely long range. However unlike your typical solo top, HE HAS A VERY HIGH SKILLCAP.

He also can fall behind very easily and become obsolete. This only happens when he is denied farm, OR when his opponent gets fed by teammates.

My general thinking is that solo top is a very unforgiving lane. It's a place for bruisers not squishies. Squishies can manage until something goes wrong (and it always does); at which point they're forced to recall or worse while the olaf/shen/garen/renekton/etc chuckles.