The build material of Galaxy Note 4 and Galaxy Note Edge is a matter of consideration. Because there is lot of news on the same. Samsung is going to use plastic elements. That simply means this phones are not durable. They lack a waterproof and dustproof design. This makes the phone a bit weak in term of selling point but I hope that in the coming time they might do some changes in the body design. Samsung might want to keep the phone weight less by using a plastic element on the same. Because if they use a metal design then it might get heavier with the big screen size.