IMHO the iclears deliver better flavor. But that might just be my preference for warm vapor and a tighter draw than the Protank.
I started dripping, and my iclear 16s flavor is comparable to and RDA... just very slight diminishment, but better than the Protanks. And I find the Protank very inconsistant. It'll perform very differently full or nearing empty, or even if just sitting a few hours.
I have 3 Protanks sitting on a shelf, while my iclears and RDA are abused daily
But that's just me.