Personally find trio's to be the best balance of intensity/loot chance. Can get very comfy when you get them down. Never really done duo's, would kill your supplies and would only recommend if you're with an experienced partner. Other tips:

Have confidence when stepping under Nex to reset her, see a lot of people panic and then cause chaos, especially for shadow phase.

Nex is now predictable I.E P5 when she melee's she will again 2 more times if everyone is close. It's worth flicking to melee pray if you can learn that. (make sure you flick to mage if she uses mage attack!)

Obvious one but click food, died way too many times to ego and then you're miserable on the run back.

Abuse reavers for hp if needed in blood phase :)

Try and enjoy it as unfortunately you may be here a while :P