No renekton is not that hard to play. People may think so, but it's pretty simple.
Just e onto them, stun with w and q. Also good to note q is more for farming early then dmg as it's pretty low until mid-late.
I really can't understand why he's underplayed, esp in mlg. He's such a great solo top and team fighter. Champions like him, swain, vlad and others I can't understand why so underplayed. Not like their the most difficult.
Also, my usual build is like this:
Guardian angel (situational. If more AP based I get FoN)