Grey Knights: Grandmaster Or Librarian?


Here is something I have been struggling with since the beginning of playing my Grey Knights- in terms of running a “classic” pure Grey Knight list- librarian AND/OR grandmaster?
Both have such a huge place in the list, but at 2000 points I just can’t seem to get both of them in and have enough points for the rest of the stuff I need- mainly strike squads, terminator support, and land raiders.
Taking just one means I can fit in the other units I need, but I switch back and forth between both of them and am still not really that happy.
First up is the grand master- he gets a halberd and orbital strike in my list and hangs out with the terminators and paladins- his ability to make my dreads, paladins, or assassins, scoring if needed really boosts the small model count of the army, and if it isn’t an objective based mission then the other two boosts are nice- but getting the extra scoring units is what I’m after.
On the librarian side I upgrade him to the max in terms of power and go for the pulls on the psychic cards if he is running solo. I’ve found that not only are the psychic cards tons of fun to play, having a psyker is very handy on the table, especially with hood support for my terminators or paladins.
So the question is which one generally wins over the other?
BEST of both worlds has me playing Mordrak with the ghost knights and a warp rift librarian attached for the first turn deepstrike which I just can’t resist not playing…