Planted a DF of this in May 2021. Despite the late planting it managed to produce me a few blooms. They were lovely. I was looking for a plant that was the absolute best bang for your buck, based on bloom-size (bigger the better) and bud-count (more the better) combined. After a lot of in-depth analysis I actually settled on Sparkling Giants (also a Pierce), but it was not available at that time, and Amethyst Prism (AP) was.
AP also has a huge bloom size and high bud count and it was at a dirt-cheap price on the LA so I got it. It is in a South-facing bed, so I am hoping for a lot from it in years to come. I will now not bother with Sparkling Giants as it is just too similar to this one, and this one is very pleasing to me. I love the triangle shape that makes it look like it is from an alien planet.