[randie63]

THIS!

MTP sucks hard and is slow and easy to overload with many files.

My 4.2 device was Umi X2 Chinese phone and I even hacked together couple Roms for such Meadiatek based devices back then. I remember my lightest ROM was like 250mb. With working PlayStore and all, but obviously only bare minimum included. Nowadays even the lightest custom Roms are 700mb+ . With Google apps and all easy 1.5GB and more.

[throwaway2056]

Look at https://github.com/SelfAdjointOperator/better-adb-sync

forked from https://github.com/google/adb-sync

Uses a syntax like rsync via adb.

[Jiro]

You're probably better off using adb. (Which does have its problems, like not handling copying directories well).

[causality0]

These days I just use a network file browser to copy files. Easier that way.