Jaster M said what I pretty much would have. These, to me, are clearly hand-painted prototypes or hardcopies of some sort.
Plastics used can vary, but I highly doubt Hasbro would go through the trouble of using "superior" materials in making these figures. The plastic Hasbro uses on 90% of its figures is of a high enough quality to pull very intricate detail already. What's used on their weapons most of the time (though I've noticed a slight change for the better as of late), and that odd battledroid-ish figure who can't stand up, well that's another story.
I wouldn't expect these figures to have a better plastic, nor worse though either. Since I do believe these are hand-painted figures though, I think you'll see that they're not as "crisp" looking, which is the case of just about every figure we see in the line who we see prototypes of before we see production figures. Sometimes they even look worse, like the Adm. Ozzel prototype compared to his production figure who looked far superior.