Ok, some context might help where I come from here. With my main group, we misread this rule and basically applied it with the "free armor first". Meaning that most of my character have synthleather as armor (Armor 4) because anything else give them dreadful Agility bonuses. And honestly, we are happy like that. It make the game a bit more dangerous, which we like.
Now, the silly thing with this mistake we did, is that most armor are indeed out of reach. What I don't like about the regular rule is the lack of malus if you are wearing heavy armor.
As I agree with the comment of my rule making Body too important, I've changed my rule to (Strengh * 2 + 3). Now, let's try to make you guys understand where I come from with this, by using a very, very concrete example. In real life, I'm not a strong guy, in Shadowrun I would probably have 1 or 2 in Strenght. If I were to be wearing an armor vest, I'm pretty sure I'll be encumbered enough to have a malus in both my Agility and Reaction.
A regular Jo, more biffed by me, (Str 3) would probably be wearing the same one without any maluses. If the same regular jo was wearing a combat armor (let's say 14 armor for simplicity sake), I would expect him to have some maluses to both Agility and Reaction. Thus my previous idea of having 9 as a threshold to start having penalty. In this context, regular Jo would get -2d maluses, which seems fair.
Now, moving above regular Jo, let's talk about Bob, security specialist, Strength of 5, can wear up to 13 point of armor without any maluses. (in previous version, the same Jo would probably have 5 in both Body and Strength so it would work).
Oh and btw:
Bushw4cker, that idea would make a Troll with cyberware armor nearly impossible to kill. Not only do they roll 40 dice to soak damage, that sniper shot that did 20 DV only does 10 DV now.
This is one of my issue. If you start rolling 20d to soak, you can soak a lot - way too much to my taste. I like my Shadowrun game a bit more closer to the vest (not an armored one). Basically, you can probably get shoot a couple of times, before it start to hurt too much or just be down, but not more...
@ZweiBlumen: FYI, our game will be unaffected, we'll apply the rule as describ in 5ed