Has someone tried to instead of rolling BOD for soak to (only) roll armor?
It would take away BOD's primary function, making it a dump stat at that point.
I haven't tried this yet, but a house rule I proposed is to replace Intuition with Armor in the Defense test. This would increase lethality for unarmored targets, maintain a pretty similar lethality level for PCs, and decrease it slightly for heavily armored targets.
The problem I foresee with it, and with any house rule that involves armor that adds dice rolling, is that augments and powers that provide armor are really cheap. Right now, characters with cyberlimbs can get huge armor numbers. Physad Mystic Armor can be level 4 for 1 PP. That's forgivable when armor doesn't really matter, but would be unbalancing if they translated to defense dice.