Lico slotted molten whip on stamDK parses just for it's proc (without using it), so you may guess that on magDK it rocks.We need dps testing to see if the spell damage increase to ardent abilities is overall better than the overall damage you get from flame last procs for pve. I think up time is everything for pve dps so Iam leaning towards whip for pve. I use lash for pvp where it gives you nice burst damage for those pvp encounters and a nice heal you can use, nonetheless some testing can put this to rest.