First of all, the conclusion is that Unhallowed Essence 6 Pieces bounus still need to be buff 3 tiers(6-P 1700% bounus→3000% bounus), otherwise it cannot compete with Hungering Arrow and Shadow Impale.
According to the 2.7.5 PTR update just released, 6-P of Unhallowed Essence set is 1700% bounus, which has been improved by about 10 tiers. I can fast clear 115 GR with 10K Paragon about 50K Dex by Multishot in non-season on Patch 2.7.4, which takes about 4 minutes to 6 mins, while Hungering Arrow takes about 2.5 mins to 4 mins fast clear GR125 and Shadow Impale takes about 3mins to 4 mins.Therefore, if Unhallowed Essence can’t continue to buff 3 tiers, then this Set will not compete with Hungering Arrow and shadow impale.Unfortunately, the change of this Set (6-P 1700% bounus) is meaningless.