ADB in my experience is much faster (and less prone to errors) to transfer files from the computer to the telephone.
I know that install and connect with ADB is not so straightforward, but the protocol have significative advantages over MTP, and you don't need to change the connection type all the time (In the cellphones that don't want to remember what you choose), and by the way that ADN works, (with commands) I think it should be feasible to implement it.
Also with ADB over network it could also be added to the current app in for wireless Sync.