Well I'm stuck installing, I've unplugged all my USB devices and it's still not moving. Sigh!
Any progress since? I've noticed that that made all the difference because when it'd get stuck it would say "Calculating time remaining" without any indication of the amount of time left and stayed stuck like that a good 20mn. As soon as i unplugged my phone and the two USB drives I had plugged in, the "Time remaining: xx minutes" appeared immediately right after and it started working again. Notice that change at least? As long as there's a time remaining, it is working.