I just moved a file from a NUC with Ubuntu and the built in network card to a Dell XPC13 with a USP type C to ethernet adapter and Arch linux on it. Both connected to a Linksys router with a Gigabit network.
I moved the file via sftp. The UI showed a speed of a little bit over 100 MB/s which seems to be really close to the theoretical maximum of 125 MB/s. Cool shit!