Ive had a few a/m hulls, most of them arent any lighter than oem. You can buy 3-4 oem hulls for the price of some of the top dollar hulls, so be sure to factor that into consideration. You can get a sj copy or you can get a hybrid. If i was going with a am hull that was a sj bottom copy, it would have to be lighter and stronger than oem or its just not worth buying. I switched to a hybrid hulls so i could run the motor/pump combinations I like. I currently have a eme signiture series hull which is light, balanced and handles better and feels more comfortable than any hull i've ever owned or ridden. The downside is its not gonna last forever and will need to be replaced someday.
Ive had good and bad products from wdk, I broke the bottom of my rev hull, to the point it was junk in the first day and on the other side, My original xjet hull lasted 7 seasons. In Jeff's defense, he did warranty my rev hull, but it took a couple of years. Unless youre just really lucky all the time I'd stay away from wdk, because the 50/50 chance you get a decent hull is not worth risk of losing seasons of riding. The highest quality hulls I've personally seen are the trinity hull and the german lightweight.de hull. After my current hull no longer floats, i will prolly be going the trinity way