I said I wanted to go over the units in depth and I am going to start at the top. I am going to put the Grand Master and Brother Captain together as these guys are almost identical, but will brief over the differences.
So firstly, the great Grand Master, there are now apparently only 8 of these guys and never any more than this and we know that two of these are Draigo (Supreme Grand Master), and Mordrak (the guy with the ghosts of christmas past). You would think that these guys must be the ultimate killing machines as they have survived countless battles with Daemons and even had to hunt 6 of the deadliest on their own to become Paladins first (apparently). The Grand Master Sports a WS and BS 6 which isnt bad, he also comes with 3 wounds and Initiative 5, sounds good so far. But, he only has 3 attacks... and has to pay 10pts for +1 attack, he comes with Terminator armour as standard and carries a Nemesis Force Sword (+1 invulnerable in combat). This guy weighs in at a hefty 175pts, but, despite not being a monster in combat he has the Grand Strategy ability to give D3 infantry, jump infantry, walkers or MC's (not including Independants and Henchmen) one of four abilities, these are:
Re-roll To Wound rolls of a 1 for the duration of the game.
claim objectives as if they were troops.
The last of these is a HUGE bonus in an army which relies on its Elites and Heavy Support as much as they Grey Knights now do.
As for his wargear choices, he can take the standard Grey Knight equipment of:
Halberd (+2 Initiative) for 5pts
Falchions (+1 attack) for 10pts
Warding Stave (2+ inv in combat) 35pts
I normally keep him with a Force Sword as he gains a 3+ invulnerable in combat, but I may consider the Halberd as Initiative 7 would help against other HQ's the other two options (especially the warding stave) just seem too expensive for what they do. The Grand Master can also take any of the "heavy/special" weapons that Grey knights can:
Incinerator (str 7 Flamer) 5pts
Psilencer (Str4 AP- heavy 6) 35pts
Psycannon (Str7 Assault cannon) 45pts
with these I would keep him with his Storm Bolter, or maybe give him an Incinerator if I really felt like I had to upgrade it, the other weapons are just too expensive to consider when they are much cheaper elsewhere. He can make any of his weapons Master Crafted for 5pts per weapon, I would only consider this on his Close Combat weapon as his low amount of attacks mean that hitting is critical.
The Grand Master can be upgraded to a level 2 Psyker for 35pts, meaning he can cast either of his two psychic powers and still use his Force Weapon, or just got for two psychic powers.
Lastly, the general wargear:
He can take up to three Servo-skulls for 5pts each (these guys let you roll 1D6 scatter for Deep Strike and Blast weapons within 12" of them, and stop enemy infiltrators and scout moves within 12", but if the enemy moves within 6" they dissapear)
Blind Grenades (defensive, so -1 attack for people charging him), Meltabombs, digital weapons (re-roll one failed wound) for 5pts each
Empyrean Brain Mines (nominate one enemy model in base contact, they must pass an Initiative test of cannon attack that phase) 10pts
Psychotroke Grenades (these do all sort of things that can be helpful but it is luck of the dice), or Rad-grenades (-1 enemy T the turn they assault or are assaulted) for 15pts
Orbital Strike Relay (this is like the old Orbital Strike, but the bearer cannot move, but can assault, and you can shoot one of three options) 50pts
For these, I would consider Servo-skulls if you have alot of blast weapons (not many here to be honest) or a Deep Striking army, but they are cheaper on Inquisitors. The digital weapons are worth considering as it only takes one wound to kill with a Force Weapon, as for the rest, I think they are too pricey to consider on an already costly model.
Now, onto the Brother Captain, this guy is almost identical, but only has a BS 5. he cannot be upgraded to Psychic level 2, and his Psilencer and Psycannon are 5pts cheaper. He also does not have Grand Strategy, but costs only 150pts, He does keep the Psychic Communion and Hammerhand Psychic powers though. Psychic Communion allows you to either Add or Minus 1 to each reserve roll you make, but the user must start on the board.
So there you have it, I personally ALWAYS run a Grand Master instead of a Brother Captain as I think the Grand Strategy is well worth 25pts. However, I don't give him any upgrades as I think he is expensive enough and the squad he is with can usually help deal with any threats he meets. I will let you decide which you think is best though.
Until next time