Thoughts on xp loss as a Diablo 2 Vet

Yeah, the experience loss mechanic was introduced more gradually in PoE1 as well. You'd get the 5% loss on going to cruel, then 10% going into merciless irrc. Once they made the ten acts, it became 5% in part 2, and 10% in end game. Your lost resistances were also based around wounds inflicted via a god in that game, too. There's not much clearly telegraphed explanation on why you're losing resistances while climbing the acts currently, nor excuse for the experience penalty kicking in.

Maybe there will be when all six acts are released, but I think they wanted to make experience loss only an end game thing to make the campaign more accessible to people, so who knows.