I agree with your assessment. I was the first person in VA to own a SCUBAPRO jacket, purchased in 1977. I used it for 14 years and it was wonderful. I would never look at an "Atpac" wing again. However, when the jacket was totally worn out, I replaced it with a SCUBAPRO "double black" adapting the original, high quality, hard pack and metal clamp with nylon waist strap. I was unhappy. Discovered the that the skirt was two inches longer which made it difficult to access my fish stringer, etc. It had two huge pockets which made it bulky.
Later, I bought a slim tropical model which had a short skirt but quickly discovered that it was a poor design. The arm holes were too large which allowed the tank to move all over the clock. I then bought a Beauchat adjustable "Master Lift" which is compact and very nice but still allows the regulator to bump the back of my head.
Lastly, I found a Seaquest 3 Dimension which is a back inflating softpac(small plastic back plate) and which employs the most wonderfully complex system of cantilevered straps and tensioners that I have ever seen. I could never have thought of it, but in spite of the complexity the Dimension is actually simple to use. All adjustment takes place at the waist, pulling on the belt ends automatically adjusts the shoulder straps. Once in place and adjusted, this thing fits like a glove. Removing the unit is simplified by quick release buckles at the shoulders. It has superb balance and is not bad on the surface. It packs flat and compact. It has no pockets, though. These vests are no longer in production and are fairly rare but it is verrrry nice.
I have no special case to make for back mounts in general. I am still leery of the over hyped "wings". One thing, I don't understand the comments about being "squeezed" by jackets. I dove the original Scubapro stab jacket hundreds of hours without any such problem.