Shareit is a good app for data transfer. It take a short time for tranfering the data. If you are transfering 3 GB so it will take approximity 10 minutes. I think it is a good speed. It has a lot of features like connect to pc , web share , detect junk files , privacy protect , phone replicate and many more. You can transfer anything like apps , pdf files , images , videos anything. If you change your picure at shareit you will see your pucture in your own phone and you will tranfer file so it changes in others phone. If you want to see the real speed so shareit is the best option.