Well, a nice ethereal CV dropped just barely for me today. The problem is, it only has two sockets. I've been looking for a 4os polearm to make insight with for a while now. Could I resocket the CV to 4 sockets using the socket quest from act 5, or is it a lost cause?
Well eth monarchs can get somewhere 3xx def (with cube, 333 I believe) and you can give them to a merc @ act 3 so they are useful.
I think I saw someone making a phoenix in one, too, for merc.
Not sure how many people actually use them as most prefer a2 nm aura mercs.