PL language added; will upload later. Thanks.
About the armor stats.
I think your stats make sense in a context where you consistently encounter enemies using AP weapons (and probably this how it is in Dioxine's mod).
In the case of a lone armor however it could be used in any context, including vanilla. In vanilla, where you basically face plasma (and esplosive) attack only, with your stats I think it would be too useless (only the front armor have a significant value).
See, that's why I'm not a big fan of human armours in X-Com. I totally agree that it's not very useful, but then again, that's how it logically should be. Kevlar and ceramics must be crap against plasma, period. This has nothing to do with the Piratez mod, which uses completely different philosophy.
I can understand a little compromise to make the armour a bit more useful, but on the other hand, I don't think it's worth the damage it does to immersion.
...unless it could be unlocked by some early research maybe? Worse than Personal Armour, but still somewhat resistant to plasma? I just don't know.
Therefore I think using "general purpose" armor values, instead of special damage modifiers, is better: it makes the armor consistently equally useful in any type of context.
Yeah, true. However, while it's not a problem with fictional armours, it's not as simple with real life designs.
Sorry my post is not more constructive, but I guess that's all I can do...