I have finished phase one of my assessment on the Dhampir for this preview
They are defensively weak, I built a melee Favored Soul Undead build Dhampir, I pulled out all the the stops so I could steel man the Dhampir, Steel manning the Dhampir to argue it as a good race as it failed. While the Dhampir performs above average in low level quests in terms of what its racial tree offers, it is defensively far too weak to release as if on this preview.
The balance of offense and defense capabilities though make the Dhampir great for soloing an individual boss type monster if you max out all of its capabilities, but it can't handle mobs beyond that rush of bats buff. Soloing Reaper 1, yes only 1 becomes a near challenge. Not because of the negative healing amp aspect, but because this race is oddly squishy, as if they have some sort of hidden defect.
Phase two will be a Dragonlord fighter build