You would have enjoyed the beginning of Legion when this build was king, though prepared was taken then because it helped with the momentum buff window. People stopped using it because Bloodlet was nerfed though, and then it because of that the it was no longer worth using such a risky playstyle since fel rushing for dps can potentially get you killed in a raid, or at least make it so you don't have your movement abilities up when you actually need them.
Anyway, I quickly messed around with this on the dummies in the order hall for a couple minutes each, both single target and aoe, and got like 1.5m single target and around 3m on the aoe. Which surprisingly enough is better than I thought it would be since my secondary stats are for tier 21.
For comparison, I get like 2m or more when rng is on my side single target, and 4m or more on aoe with the proper set up. Though again, that is after a couple of minutes, not out of the gate.