Where to level? World tier 4, lvl ~68?

I just hit world tier 4 last night with a twisting blades rogue. I kill stuff fine, but I'm a little squishy, but I'm sure that gets with time.

I remember pre-season 1, that different drops happen at lvl 80? So I've been saving some of my better rolled aspects for the Ancestral stuff. Is there an optimal spot to grind?

I've mostly just been doing the vampire stuff(blood harvest?) + helltides. Any recommendations would be welcome!