I think the title and description say it all -- only the highest rating is used now? We don't add half as much again from stacked armor (unless a "line" of clothing is used from Arsenal).

For most armor, yes. There are exceptions. The most notable ones are Form-Fitting Body Armor, the SecureTech PPP System, and Helmets and Shields. Some others that stack directly include natural armor and cybernetic armor (Dermal Plating, Cyberlimb Armor, etc.), which is essentially treated as natural armor.

It should be noted that even if you're not gaining the benefit of a piece of armor, it still counts fully against your encumbrance unless a piece of armor specifically states otherwise (which is the case for natural and Form-Fitting Body Armor).

So, if you're wearing an Armor Jacket (Ballistic 8/Impact 6) and a Chain Mail Shirt (Ballistic 3/Impact 7), you'll have Ballistic 8/Impact 7 but 13 points of encumbrance due to the stacked Impact ratings. If you threw on Form-Fitting Full-Body Armor (Ballistic 6/Impact 3) onto that combo, you'd have Ballistic 14/Impact 10 and your encumbrance would increase by only +3/+1 (or 14 points of encumbrance total) since FFBA is halved for purposes of encumbrance. So if you had a Body of 7, you'd be sound as a pound. Anything lower than that, and you'd be suffering encumbrance penalties.

Edit: Man, that's a crappy example. Sorry about that.

Basically, yes.


House Rule
Armor Encumbrance is determined by comparing Ballistic + Impact values to (Strength + Body) x 2. For every 2 points of armor in excess, you suffer a -1 Dice Pool Modifier to all tests involving Agility or Reaction.

Multiple pieces of armor stack. For determining Armor Encumbrance of multiple armor layers, apply the highest armor value, then twice the armor value of each additional piece. Armor modifiers (+2 to Impact from helmets, for example, applies to the highest base armor you are wearing, & thus is never doubled).

Form Fitting Body Armor, if worn by itself, does not encumber a character. If worn in addition to other armor, is applied last but is not doubled for determining encumbrance.