well.. all of these paths are used for each situation, for example:

I use DPS/AP kog'maw against tank/offtank champions
I use DPS/AD kog'maw against autoattackers
I use DPS/Crit kog'maw against ranged champions
I use my real way with kog'maw against another champions...

The rod of ages, for example... i use it to create a new hybrid situation(well, kog' is very weak if ganked or something else like the dominion turrets... so rod of ages gives to kog survivability and mana, to use skills without go back to get more mana e.e

Its just that your builds confyze me a bit.You dont do str8 ap,you dont go str8 On hit effects.Are you trying to make a hybrid situation??.I dont know if that would work better than other item paths.

oh, someone see this \o/

I do ^^.

Omg... no one see this '-'