Putting aside their painting methods until later to focus more on their use in-game in comparison to the last ruleset the Stormtroopers have, in general they are cheaper, better in bulk, and using them is wholly more risky if you stick to their former play style.
I've got a legacy of being underwhelmed by the rules for Scions. In the past I've been OK with the one-shot-pop-squad, with 2 meltaguns which can deep strike for a little over 100 points, really I was.
Now they are cheaper, even with meltaguns. They are still a costly gamble, which is heavily influenced by terrain use, but still worthwhile.
Allow me to explain. As the squad has the Move through Cover special rule, deep striking into area terrain is now massively safer, and likely all of them will survive. However, both I and my local gaming group have relatively little area terrain, or buildings with large battlements, (or wide open roof ruins) and instead have large amounts of 2-3 story ruins.
Ruins = supporting walls and rubble.
Admittedly most of these lovely pieces have some portion of flat space, where a five man blob can just about sit. This is generally the roof, where deep striking units cannot be deployed. I know also that thematically most ruins and are designed to have more flat space as you go upwards, whereby any broken floors and walls will fall to the ground floor, where deep striking units must be deployed.
|No room at the Inn!|
Being at the mercy of that deep strike scatter dice roll is not fun. And is incredibly nasty if scattering into a massive block of rubble, an enemy or a wall. Also, if remaining as a melta-pop, you'll be tempted to put them closer to the enemy to ensure you get that extra d6 for penetration. Again, another mishap incoming.
|Go to the right! Always to the right!|
Drop them into what little area cover you can find, drop them into the open as necessary, or (controversially) don't drop them at all. Stick em in your gunline with the meltas as a deterrent, or stick Volley guns on them and wait for someone to charge you. For less than 100 points you can chuck out a lot of BS4 hot-shot shots (ahem).
From their rear, they look more tainted, with the ad-hoc weapons and the skinned flesh faces.
Aside from a glistening coat of mucus on this guy, they're ready to go.