It's been a while since I've posted so I figured I'd give a progress report on how well my tempestus have done. . I've been using them mostly in 250 to 500 PT games mostly due to lack of models. And you could say they play like hybred guard and dark eldar. Vehicles lead the way but, with the various orders and hotshot laslas guns you have quite the arsenal AR your command. The thing is for tempestus, in my meta of course, is that I need something more threatening inn.y army. I have about a 50/50 win loss ration in what gam s I've used them and it seems that all I need is more pollish and they will be a force to be reckoned with. I plan on allying with a knight gallant, and an inquisitorial warband for some close combat potential. I also plan on bringing a valkyres squad to deal with flyers. The only thing is to acquire the .models and get them painted.
As far as how the weaponry does for me, I'm a big fan of the tarox Gatling cannon/hotshot volly combo. 4 ap3 hits against marines is never a bad thing, the only problem is the weapon is set so far back on the prime. Other than that you want to be in the 18 inch range for your hotshot weaponry just in case you need to snipe something, so it complements the base weapon.
As far as special weaponry goes, I suggest a squad of melta scions or 2, and plasma gun scions as well. The thing to remember is that you may only carry 2 weapons in the squad. But now I realize you do want 10 scions per squad.imagine what happened you you have to kill a mo steroid creature that even a plasma gun has a hard time hitting, say a wraithlord, daemon Prince, riptide, or any of the big bugs, the elimination protocols work for ALL weapons, so yes, you can turn a plasma gun into a sniper rifle...with all the rules there in, save heavy.
So there is a progress report please keep coming back for insights on this, while limited, versatile dex.