Merely enumerating all the files in my 4chan image folders over NFS in a Gtk3 file picker took 15+ seconds. On Windows 10 it takes less than 5 seconds. Same hardware, same network, fresh installs. Gtk3 does this EVERY TIME, with no caching.
The folder tree in question:
$ anon@nas:/data/pics/4chan$ find . -type f | wc -l