Go here: EPEC Nitrogen - Controlled-Release Fertilizer
At the top EPEC is: "premium, high-quality polymer-coated urea"
Under 60-day: "excellent replacement for PCSCU"
So EC Grow is replacing PCSCU (or PCU) with PCU? WTF
PCU and PCSCU fertilizers have been around for quite some time. They are just putting a coating around some of the nitrogen in the bag. Thicker coating => longer time to break it down and release.
Now manufacturers are trying to time exactly how long it will take for the nitrogen to be released. I would not trust anything beyond 90 days. There will always be an excuse from the manufacturer: Too much rain, too many bugs, too much heat- that's why it broke down too fast.