Javascript based networking?

So the idea is, send strings of javascript from client to server and vice versa and when a client recieves it (or the server) it will eval it and do something with the code. This would allow for things such as server mods, speedy connection (I think) because there would be no need for packets, and also simply the support for client mods.
So i’m stuck. I’ve already scrapped my original design for the networking in my game and started to work with kryonet. So before i scrap my kryonet code, I would like to ask if any of you people out there know of any bad things or good things that could come with using javascript? Thanks!