I ran a pacman -syu and noticed kernel 4.14 on my odroid-xu4 today. I was excited to see odroid-xu4 making the 4.14 jump, but after issues with previous major kernel jumps with this board, I was also concerned..
So before upgrading, first thing I did was come here and search for issues. I saw no issues reported and decided to give it go.
Happy to report - all good! Thanks so much to the devs of arch linux arm for maintaining the superb ARM port of Arch and for a smooth upgrade to 4.14 on odroid-xu4! Cheers!