The ok/ez line has been around for quite awhile.The biggest difference between the two is the construction technique.World models builds their airplanes pretty much like you would,and are covered in basically what is ultracote.The ez line uses that foam backed,preprinted mylar covering type,which also adds strength to their planes.The major advantage of world models(just my opinon) is they are easily repairable.The ez line,even with a puncture hole is near impossible to get a good looking repair done .Ez was definitley the best years ago,but as far as I'm concerned the world models line is top notch.