So far we have seen only a handfull of the 14 armor classes listed on the cards (there are 4 infantry, 7 tank, 3 aircraft).

From what I have gathered, from teh core sets we see Infantry 2 and Infantry 3 as well as Armor 3 and 4 and 5 (Anti Tank traps are AC 5).

Am I missing anything?

Sounds right, we don't know what the Heavy Walker armor will be yet. At the rumored around 100 points per Heavy Walker, Those might be an armor 7 maybe?

You know, I was flipping through the revised core the other day and something came to my mind...

On infantry armor 4 entry, it says something like "far more than anything seen on earth in 1947"...

IT´S ALIENS!!!! ALIENS PEOPLE!!!

Vrill infantry WILL be armor 4 infantry. That´s my take, and I would bet on it!

Im thinking the heavies will come in at armor 5-6, more than likely 6. Any other beefing up will come from an increase in wounds. Main reasoning is that it will still leave room for growth later in the game. If they release Armor 7 units now it kind of locks them in as the stat cards dont have any room to go beyond that level. And as Aldarion said currently there are no other human forces that can get to level 4 infantry.

Aldarion said:

I think you might be very right. The current heavy infantry is about as armored as you can go with the units still looking like people in armour, instead of driving mechas. But with the aliens, the soldiers themselves might be larger than humans, with biotechnological armor or whatnot, which would make them very tough. It makes sense to differentiatiate the aliens like that, no squads of five people, just powerhouses of a couple of figures.

Agreed. Armor 4 infantry would pretty have to be something far beyond what the current armor looks like. Figures crossed for more advanced alien tach.