Discipline and self-sacrifice - these are the qualities that make up the elite of the most humane of the legions. In essence, the Firedrakes are terminators with 2 wounds each, a bonus to WS, and all in cataphractii armour.
The question to my mind is whether this extra wound is worthwhile in comparison to a regular legion terminator squad? I'm a bit on the fence and could be persuaded either way here to be honest. On the one hand, its a bit like having double the number of terminators in the unit. But on the other, they can still be instant killed by vindicators and the like.
On top of this dilemma, and something that might well be the swinging factor, is the ability to create thunder hammer and storm shield terminators. But it comes at a steep cost.
Here's the builds to think about.
5 Firedrakes, all with Thunder Hammers and Dragonscale storm shields (350 points)
That's a whole lot of points. But certainly comparable to a 10 man regular legion terminator squad in points cost if you logic that there's the same amount of wounds. Take a land raider, (or pride of the legion rite of war for teleportation purposes) and you're good to go basically.
10 Firedrakes, all with Thunder Hammers and Dragonscale storm shields (625 points)
I think you'd want a guaranteed no scatter deep strike for this lot. But a big land raider would also do in a pinch. Its a gamble: you're putting all eggs in one basket. But its very cool! Particularly if you're undertaking Istvaan mission.
5 Firedrakes, 3 combi-meltas, 1 heavy flamer, 2 chainfists (320 points)
Whilst I'd be more tempted by the thunder hammers and storm shields, this tank hunting variant is also going to be a pleasure to run. Its a bit like a termicide squad for tank hunting. But it'll last longer due to the extra wounds.