Apparently you aren’t the only one - this other user has problem with their EX4 (not EX2) update → http://community.wd.com/t5/WD-My-Cloud-EX4/Reboot-after-firmware-upgrade-taking-forever/td-p/783057
My upgrade for EX2 went smoothly yesterday night though and did not take more than 10-15 minutes (my earlier mention of multiple firmware updates were for Sunday when upgrading to a previous firmware version - but not using automatic method but manual - I prefer manual ALWAYS and have auto-update turned off).
