>>8252168This picture shows a breakdown of the internal changes. Now instead of the side pockets being attached to the ab section, they're hard plastic and are attached by a hinge that's sandwiched.
The ab section is its own price that fits over the joint behind it, and now the ball joint is locked into the chest panel.
There is a big issue with the legs detaching whilst posing, and it's quite frustrating, so the 1.5 fixes it. The neck was also changed, and it now has a hinge for better poseability.
I may be missing a few points, but in terms of which is better, it's ultimately 1.5
You'll just enjoy it so much more
