I'm still not sure where to start with the Daemon codex. 2d6 Assault range, Fear seem to help a heavily assault-based codex. Transitioning from 5th means joy as No Retreat! wounds are a thing of the past. But now there's also Overwatch...
I'll start with Troops. Generally, the stronger the Troops, the stronger the codex.
Bloodletters
Combine their power swords with Furious Charge and they still pack a decent punch against most infantry. Bloodletters are still only T4/5++ models and to be effective really need to swing at least at the same time as the enemy. This limit means enemy Terminator squads are going to need to be dealt with on different terms. I finished 5th Edition running a squad of 15 Bloodletters and they were very effective. Now I'd consider the same squad for a few other reasons: Overwatch and 5+ cover. To be survivable, squads will need to be bigger, which leads us to figuring out the break-even mark. When does it become throwing good points after bad? Bloodletter reach their limit well before 20.
(And yeah, the above paragraph got heavily edited to reflect the accuracies of the FAQ and the original inaccuracies of my recently rampant illiteracy.)
Daemonettes
Rending claws are counted as having two close-combat weapons, so the Daemonettes are looking at 4+ rending attacks per round at I5, plus offensive and defensive grenades. Sounds good enough, but... they're still only T3. I just can't stress how hard they'll die. If you're set on running them, I feel it's the age-old adage, Go Big or Go Home. It is possible for the Daemonettes to handle anything in game in assault, so maybe it's worth considering. 20 of them won't get stuck in against a Walker like the other Troops choices. But T3, in a ruleset that encourages the dakka, I just can't be seduced.
Plaguebearers
Between cover-nerf and Feel No Pain "adjustment", these jolly fellows didn't make the transition to 6th so well. They're still rockin' Poisoned weapons, which work just as well as before. And they're still T5, making them the most durable scoring unit. Maybe you take some for your backfield objectives, which leaves Plaguebearers the same function as they had in the previous edition. Sit on objectives, stay out of trouble and don't die. Exciting, yes?
Pink Horrors
They shoot, which is a novelty among Daemon troops. BS 3 is not much to work with, and with low expectations like that, you could feel comfortable taking the long shot at Flyers with Bolts of Tzeentch. Pink Horrors are the only Troop choice for which I'd consider taking only 5 models. And sometimes, that 4++ save will really surprise you!
Nurglings
It is the fool who underestimates the Nurglings. They are the clear winners of Daemon troops for 6th Edition. Their role is still the same as the perfect counter-Death Star unit, a big pile of cheap Wounds that will take a beating for rounds and rounds while the rest of your army handles what's left of your opponents. Point Nurglings at your problem and ignore it! Big baddies like Mephiston spend turns squishing tiny poopsmiths. You can hide these little buggers very easily too! If you're running a Nurgle/Epidemius list, this should be a no-brainer. Imagine the wild possibilities with a fully-charged Tally!
