The most probable it's too soon for S5 owners to make the upgrade to Samsung Galaxy Note 4, but a great moment for people who already have Note 3 and even Note 2 phablet.
In just a few words, it's an upgraded Samsung Galaxy S5:- bigger display (5.7'' Quad HD Super AMOLED), with a bigger resolution that pushes the clarity of images beyond the limits of human eye;
- bigger front camera (3.7 Mpx) and Optical Image Stablization;
- bigger battery = 3220 mAh;
- fast charging;
- Virtual reality - Samsung Galaxy Note 4 is compatible with Oculus-powered Gear VR headset;
- Snapdragon 805 quad core CPU @ 2.7 GHz;
- 3GB of RAM;
- minimum 32GB internal storage memory;
- and... it's more expensive!