Siege plus Thunderhead = meh

So I've been playing a lot of games with Siege lately, and while I have a fair amount of experience with Cygnar, I haven't played him much until now. I must say he is a powerhouse, but the gobber is a must buy with him. Getting two shots with his rocket launcher is pretty sweet. I sent a bunch of games with him trying to use a Thunderhead for max carnage on his feat turn. However because I can't find any sweet movement tricks to increase the T-head's threat range, I'm going to drop him from my siege lists. Right now my big issue is whether I want to use Long Gunners or Nyss Archers. Both are super sweet units, the Long gunner can fire twice a turn and can also drop a 5" suppressing fire template against stealth infantry. The Nyss are faster, weapon-masters, pathfinders, and hunters but otherwise shoot about the same, but with out the double shot when stationary. Right now I'm leaning towards the Nyss as I've ran into some stealth heavy lists that really limit the Long gunners, while the Nyss are fast enough to attempt to outmaneuver a stealthed force and alpha with weapon-master charges against heavy beasts/jacks. Long Gunners are just so brutal on Sieges feat turn, if you can hit two different targets with there pow 21 CRA. Dice +11 is good against a Khador Jack or Dice +13 on a Cygnar heavy.