I have one hen, the one with the worst bare and sun damaged back.... she will not tolerate any type of apron / saddle on her back, I have tried more than one, everyone else is fine with them, but not her.
So far, the "Hen Saver" is the most expensive and the most tolerated. But, the Hen Saver has a "notch" in the design just at the tail, and, my hens with the worst bare backs are also bare just above the tail, the Hen Saver Apron does not cover that important spot. I have seen some feather re-growth on some hens and not others. And, it certainly appears that they (at least some) will be apron wearers for life. I took them off the ones with feathers growing back in, and they immediately lost those new feathers to the rooster.
I have not tried the "apron" from MyPetChicken yet; but intend to next.
If I had time, I would try making some myself.