I have Guitar Pro 8 hooked up to Ableton Live

What do you mean by this? I use both programs but don't don't have them connected in any way so I'm curious on what I might be missing out on.

One thing to keep in mind with something like Syncthing is where the physical location of the other machine(s) is. The nice thing about cloud storage is that your data is in an entirely different geographic region, so if there's a hurricane, flood, fire, etc. your data is still safe. That being said, I use Google drive at the moment so I'll also be keeping an eye on this post for alternatives.