I assure you it's The Edge, and not another cultivator. I little back history; I originally picked up The Edge, along with Robina, Casablanca and Stargazer from a vendor at the Philadelphia Flower Show in the spring of 2015. Since I needed to clear out a space to plant them, I planted some of them in large pots on the my deck, pictured here. You can see The Edge in the upper left, along with Stargazer and Casablanca.
Later, I transplanted them to their new bed, while most of them were still blooming, this since I wasn't sure if they would survive wintering in a pot. I planted The Edge to the left of Robina, which had already spent it's blooms. You can clearly see The Edge still in bloom, with Casablanca to to the far right.
This year everything came up and is in good shape, except for the fact that The Edge is white. I know it's not Casablanca, because the flowers are too small, and Casablanca is probably still a week away from opening.