As I'd mentioned I'm also a codex marine (And other marines long side that, but the codex are my favourite) player, and thought I'd post up a breakdown of the units in the codex and my personal views/opinions of how I rate them.
The first batch will be the HQ's and special characters.
Gone are the librarians of old who could fight IMO, the codex ones are now more support characters with some combat bite. Sadly though the codex ones get less useful powers than the blood angels or space wolves, but some still have their uses.
I’ve found Null zone while effective not used a lot unless you’re fighting Daemons or units with inv saves, and even then it’s hard to get him close to use it and kill the unit. Works well if he’s with some TH/SS termies and you pile into another death star unit.
Gate is another useful power for attempted contesting or general movement of termies without spending points on land raiders, but again has risks.
Avenger is another handy power to roast T4 or lower models without giving them armour saves, very handy for roasting a squad before charging the remains, as long as you are close enough after or the charge remember.
Bar the machine curse power which is average, smite which is again aeage (S4 hits vs most things will still need a 4 to wound unless T3 or lower and vortex of doom which only works efficiently if you take termie armour (And if you do that a Storm shield is almost essential to give saves vs. POTW). The others are far too situational to be used in an all comers list.
The 50point upgrade for 2 powers though is expensive, and not as useful as other point sinks The only use for it I could see would be casting a power then charging in to combat and making your attacks instant death.
For equipment it’s usually just best to run him as a bare bones character unless you really want VOD as a power.
Ah the faithful, and my favourite marine HQ character. the powerhouse CC monster of marine codex's outside of SC's. I've found he never fails with the old traditional Stormshield and relic blade combo, usually hitting on 3's or 4's and then wounding on 2's instant deathing anything T3, and with 3 attacks or 4 on the charge he'll take down a few enemies, or even put a few wounds on some big creatures while having a 3++ save to any ignore armour attacks while striking at Ini 5! This can help get some wounds in on enemy super units that have low I high str attacks.
The above is what I consider the bare requirements for a good captain, although some extras if you have left over points are arti armour to make him a 2+ 3++ termie who can actually sweeping advance if not with a termie squad. Digi weapons make him even nice for 10 points and a better to wound chance, or the aux grenade launcher for a nice S6 shot before charging or a S3 blast, although remember these are luxury items, you don't need them.
Another option is dual lightning claws for 5 attacks usually wounding on 3's vs normal guys or 4's for most other enemies at a decent Ini stage, hopefully thinning them down for your Ini 4 guys to scrap with and hopefully overpower.
I've heard of some people using plasma pistols, power fists etc, and while it’s their own preference, it does add more risk to a solid CC base... you don't have much ini 5 or higher, so not using it hurts in the long term, you can easily use termies with powerfists for the S8 hits, or other units for the plasma shots. The captain’s role is one of high Ini killings to thin ranks for your lower ini guys to take advantage of and also to stop some attacks back on you.
He also works well on a bike with the relic blade combo due to the increased T and a part of a biker command squad. Jump packs imo less so as assault marines won’t give the backup punch he needs to succeed in combats.
See the captain entry, but less point efficient. Sadly the Chapter master gives no real bang for his extra cost bar the ability to take honour guard and the orb bombardment which he has to sit still to do... and in a marine army you don’t really want your HQ sitting doing nothing but firing an inaccurate blast especially at that cost. Only really useful in themed army battles.
A suport character who's best use if with a CC orientated unit. Slapping on a jump pack and putting him with assault marines does incrase their damage, but personally I consider it a still subpar role for the chaplain due to the attacks only being non power weapons. The other is either keeping him stock or giving him termie armour and thrownig him in a Land raider with some assault termies. Limited in deployment options and with the I4 he could be picked off before being useful in combats. Still, having fearless on a rearfield scoring unit coudl be useful and the cheap CC support of the Chaplain shouldn't be totally snubbed.
Master of the forge,
A weak character who allows dreadnoughts to be take n as both heavies and elites.. the only Items i'd consider are a bike and Conversion beamer. This allows him to move deu to the bikes relentless to put more room between him and his target for a stronger shot. and also adds 1T making him slightly tougher incase of counter fire. The real use fo him is cheapness and opening the dreads, which to be fair 6 rifleman dreads could be a solid gunline basis or even 4 riflemen and 2 ironclads for keep away duty.
Sadly over priced, no real stat increases and no INV saves. Limited wepon loadouts makes them not worth it for wound allocation especially at their increased prices if wargear purchased. Sadly unless you spend tons of points on relic blades and give them a land raider, termies can do this role better. also buggers to paint due to so many details, but the models look nice.
Most things they can do, TH/SS termies can do better... what they can do though is one of two things, firstly bringing a hard hitting unit to biker armies (At a cost! To make a decent enough CC biker command squad you need about 300 points imo) or as a plasma platform with the ability to drive 12 and open fire and even assault after if you wish (Bikes are relentless remember) although I have seen some players run with 4 flamers and 4 melta guns, it’s the same cost as 4 plasmas but you get anti infantry and anti tank for cheap on a T5 base with FNP.
The other option is lots of specialised power type weapons at I4 while having FNP. My favoured approach when running them as a biker command squad was firstly to take the company champion... 15 points for 1 more WS, a power weapon and a 6+ inv save? It’s worth it as he can be your first wound allocation for an ID weapon. Next I had 3 vets, each with a storm shield to improve survival s high ID weapons, 1 with melta bombs for some wound allocation fun and for anti vehicle and finally each with a lightning claw.
This makes for a nice amount of power weapons rushing in to combat with 9 attacks rerolling wounds, 3-4 attacks at power weapon level and the 4 odd for the apothecary. It’s likely to put a dent in most enemies, depending on how the captain is loaded out. The best bit is they all still have twin linked bolters, so you can rapid fire 12 shots into a squad before assaulting the remains.