You probably already know this but if you are interested in Purple mayhem you should also check out Gooeybreeder/Canna Exotics as he is the one who bred Purple mayhem. Gooybreeder and Norstar are friends and Gooey lets Norstar use his genetics from time to time.
I grew Moon shadow from Norstar(Old Mendo Haze x Purple Mayhem), and was impressed. The plants were huge, I grew them in a twelve foot tall greenhouse and I ended up having to bend and train the top two feet of the plants horizontally along the ceiling of the greenhouse to get them to fit.
I grew three females; two were very purple with lemon berry or lemon cantaloupe flavor and huge production, one with a lemon vanilla flavor large production with surprisingly early maturation(first week of Oct, but could have been harvested a week earlier) and almost no purple color, and one that was very purple with super thick stems but very little flavor.
All were super easy to grow, moderately mold resistant and three out of four were very tasty and potent. These plants actually surprised me with how vigorous and productive they were, far outgrowing two other Bohdi strains(DLA 5 and Soulmate, both great strains also) that I grew the same year. They were the first plants to mature in the garden which also surprised me considering that they were far more sativa dominant than the other two strains that were growing with them.
The packaging was nice, the seeds came in a glass vial which I thought was a nice touch and included a pamphlet describing the strain. The only slight negative I experienced was that I had a somewhat bad germination rate with these. I generally have a great germ rate and had no problems germinating the other strains that I had started at the same time, I'm not sure why this was. There was a "best if germinated by" date on the package, the recommended max time span from packaging to germination was five years, my pack was four years old. They were the smallest seeds I've ever seen, I'm not sure if size of seed is a contributing factor in how long seeds stay viable, but it crossed my mind.
According to Norstar's description, The flavor of Moonshadow is Mendo haze dominant, the Purple mayhem was used for color and structure.
Over all I would highly recommend this strain and I would grow it again in a heartbeat(I made F2's).