I can see how clear PMags would be pretty cool, if they can figure out how to do it with the same strength as their current polymer. But if they make longer lasting springs, they can just release new springs that go in the existing magazine bodies. No need to release a whole new generation of mags for that.
Now that I think about it, it might be useful to make a magazine with similar springs to the Giessele braided buffer spring. Three different springs of different strengths braided together, so the upward pressure of the spring is the same no matter how compressed it is. Figure out the optimal spring pressure for reliable feeding of rounds, and then make the braided magazine spring apply that amount of pressure whether it's fully loaded or just has a few rounds left.
Yeah I know, if it ain't broke don't fix it. It would be expensive, but if it really improves reliability then plenty of people would gladly buy just a few of them if they were twice the price of a regular PMag.