On another note, in the new Desperate Allies book, there's a new item, "Second Skin Armor," that is explicitly designed to be worn underneath clothing. It has no hard points, but seems to imply that the devs were expecting some stacking to occur within the system.
The RAW is specific in that like effects do not stack unless otherwise noted. I have not seen the DA write up but unless Second Skin Armor explicitly states that it breaks this rule it doesn't, ever (unless you choose to House Rule it). This has nothing to do with "realism" so there is no point arguing about it it's about the game mechanics.
Ah. I meant physically stacking, not stacking of benefits. Wearing multiple sets of armor seems to be expected. Such that one could still have only one effective armor providing Soak or Defense.
Fair enough. I get what you are going for.