I am a big fan of Samsung and have bought all the notes since the beginning but we always hear on thing and i never know if its true or not..
Never sell your android phone your data is not safe even after factory Reset..
Is this statement accurate even today with Knox and the default encryption??
You are right. The storage is encrypted by default. For added security, you can download apps that can encrypt the device further especially before selling it. What the app does is, it will write some random data into the device storage, then encrypt it and format the storage multiple time depending upon the security level that you have chosen.