There is never a reason to NOT bring a wraithknight. Even without easy cover saves it is still worth 300+ points against anything but grav spam.
You could take the guns off a wraithknight, No D sword, and no invul save and it would still be a good unit. Its base stats + GC rules are too good for <300 points.
I have to agree. It is one of the most point efficient units in the game and it really only has one hard counter.
"Don't take my win from me! I don't have many to claim!"
-Dandy