We have quite a large thread on our (in)famous Decimator, but I think we need to look at the new heavies and how they may affect our armies. The good news is while all look good, none seem to be a must-have warjack. However they all seem to add new layers of tactics for each respective army.
Here is how i see them:
Defender Chassis w/ 2 chain guns (and 2 open fist) they each get d3 shots or as a special action you can lay down 2 3"AOEs for covering fire.
Anti infantry heavy. I would expect to see only 1 in games under 50pts as he is a 9pt jack. Casters that have good synergy with him is Kraye, Haley, and Caine. Like most new heavies, this one seems to go well with Jack Marshals as well.
Vlad, Sorcha, and Karchev will give him fits. Irusk will need to be careful with him.
Crusader Chassis w/ shield (arm 21) and a ball and chain (Pow 17, Reach, Chain Weapon, Beat Back).
Well we will need to be really careful our Man-o-War Shocktroopers, Ironfang Pikemen, Assault Kommandos, and potentially Spriggan. He is a simple and effective warjack, but nothing that just stands out. He has a Khador-like ARM with his shield, so that will need to be something to be weary of.
Much like a Slayer, it has a melee weapon and a ranged weapon that will let you pick one of 3 effects when it kill a living model. 1) 3" Pow 10 AOE, 2) Caster heals d3 points, 3) This jack heals 1 and for the rest of the turn the target becomes an arc node, then is destroyed at the end of the turn.
I don't have a great deal of experience with Cryx, so i am not sure how this jack works with other Cryx units. The arc node effect seems potentially intersting, but again i am not sure. I would love to hear other people's thoughts on him.