Well, since gold from Kara bosses will be nerfed, so I think it is not a big deal from now.
Don't know if rogues or smb knows it, but we can use "the game mechanics" cleverly and kill Netherspite like a peace of cake. Don't know about other classes.
1) Pull the boss
2) Wait for beams to turn on
3) Vanish (idk if glyph of vanish does smth there) - beams disappear, but Netherspite will still attack you.
4) Kill and loot =)
So, in the end if lucky with chess event rogue can clear the whole instance
P.s. At first time I thought it was somekind of bug - I came to kara and thought - Huh, why don't i try him - if wipe, i ll ress... So I engaged the boss - tried to nuke him in the blue beam, but he was healing and it was charging wall for me. I decided to vanish at mine 10% )) and huh, beam were gone , and i took him down, god bless recuperate))). I thought it was smth like a- bug, like i said, but after that i killed him 3 times and don't think so anymore
P.p.s. Sorry if everybody already knows it. And Blizz too