I think the distinction in views might be which of the two elements - penal and substitution - has the higher priority.I like your term “shackled”. @Yeshu commented that the difference between Luther and Calvin was small, but it was very significant. I’ve been amazed at how powerful Scripture is when unshackled from Calvin’s “contribution” (and I don’t mean this derogatory towards Calvin – I appreciate his work in other areas, particularly on prayer).
My initial difficulty with PSA was also that it failed to harmonize with certain passages of Scripture, initially with the concept of divine forgiveness. I had accepted the PSA answer but it really never set well. As I studied, other issues crept into view. When I wrote down every passage dealing with substitutionary atonement I quickly realized that none of them defined the atonement as PSA (for an exercise, I’d suggest some here write down their definition of PSA on a dry erase board. Look up passages that confirm your definition EXACTLY. Underline those parts in blue. Underline the unconfirmed parts in red. What you will find is a biblical definition that is satisfaction/substitution underlined in blue and the PSA distinction underlined in red).
And as a graduate student studying theology I started moving more and more away from tradition and closer to Scripture. What I discovered is that so many of the blanks my tradition of PSA filled in were never there to begin with. Scripture very often defines itself – it isn’t a puzzle we need to arrange and imagine what the missing pieces looked like (or leave them to “mystery”) but a clear cut revelation from God. We didn’t have to spiritualize Christ’s death in order to make it sufficient to satisfy anything – His physical death is sufficient because He is God. And God could forgive – not because He had already collected His “pound of flesh” but because of who He is. Before that time I had never fully realized just how humanistic PSA and Calvinism could be (we thought we were the one’s lifting up God’s glory when in fact we were lifting up man’s sins).
But it is hard to change. I still sometimes say that I hold to penal substitution because I believe both are aspects of the atonement and it's just the easiest way out. I guess this makes me just as wrong as @Yeshua1 and @Martin Marprelate who do believe the position I hold is PSA.
I can see where the priorities have shifted in my understanding (although maybe subtly). Whereas I used to see the penal aspect as having the hire priority, now I see the substitution aspect slightly higher.
However, I'm not certain that those two aspects occupy the top two seats because I have developed a dramatically different view of what constitutes sin and righteousness in the first place.
In the Protestant framework, sin and righteousness are purely on the basis of works. Now, before I get run out on a rail, let me characterize it (even though I know many might balk at my characterization).
Adam and Eve were under a covenant of works. If they obeyed (works) they could stay in the garden. But if they disobeyed (works) they would be put out of the garden. They made the decision (works) to disobey (works) and died instantly on the inside and began a slow process of death on the outside. With that one act of sin (works) Adam condemned the entire human race as if we had all participated in his (works of) unrighteousness. But in addition to sharing in Adam's guilt, he also gifted to each of us a nature (whatever that is) by which we are driven to fulfill our (own works) of unrighteousness.
Now enter the remedy: Jesus, the sinless (works) One, being made similar to humans (not like us in all things), never did anything wrong (works). He fulfilled the law (works) on our behalf, died to take the punishment for our bad works, and traded His perfect works for our imperfect works. And then his perfect works are credited to our account, where we are viewed as having done nothing wrong (works).
Now, I realize I have breezed right through the atonement. But like I said, it has been a focused study in other areas which is leading me to the train wreck of the atonement.
What if it wasn't works which plunged Adam or anyone else into ruin? If there is such a thing as righteousness apart from works, is there such a thing as unrighteousness apart from works?
Additionally, if our plunge into despair is not on the basis of works, and the results of our rescue are not on the basis of works, can we rightly say that the rescue itself is on the basis of works?
Indeed, there was some kind of rescue, some kind of price for restitution made, some kind of substitution. But Jesus said the well have no need for a physician. We're told that by his stripes we are healed. We're told that we are new creations, and then we have become the righteousness of God.
Can we rightly say that God is righteous because he doesn't do any bad things? If righteousness is synonymous with lawfulness, can any of us really say that we are a new creation and have become the righteousness of God? And especially with a view of imputed righteousness only, how can anyone lay claim to "become" ? why didn't Paul plainly state that we are viewed as the righteousness of God?
See, I don't think any atonement theory can be genuine unless the practical implications can be tied in.
There are more of these non atonement issues which I feel need to be considered in a view of the atonement
and I'd be happy to share some of the scriptures which I feel run this works based sin and righteousness into a bind