@Gnimo, this is why I prefer HS too. Spamming IT is just insane to me - it breaks the entire gameplay and rune cycle of a DK. Meanwhile, with HS I hit like a truck and can cleave with ease on things like shamblers, LDW, Vali etc. Also, MTing BPC becomes trivial when you have HS because by the time the darkfallen orb goes to the other prince you'll be waaaaaaaay far ahead in threat. And if you're OTing on Kele, you can just drop HS in order to not kill the dark nuclei and use BS instead - it's not like you can lose aggro on Kele in case you're given a 30-seconds handicap.
Still, I guess you're right. In terms of pure TPS the frost hybrid does pull ahead, mainly because of the insane threat multiplier which IT has (which works outside of Frost presence too, I have noticed - ty, Warmane).