Actually I'm more concerned with the "2 minutes to 99 percent" than with anything else. That's awful quick. In any case, yes, reboot and see what happens. Watch for any messages. If it doesn't say anything pertinent, reboot once or twice more to make sure you are getting good full boots, and then go directly to the Microsoft update page and run the update from there.
In general, when an update is at a critical stage, you'll see the traditional "Don't turn off your computer", otherwise you should be OK (but, not recommended) to interrupt the update and for the most part, it will pick up where it leaves off.
I've done 7 of these so far and got through all of them with minimal stress. The only one that gave any real issues was the Win7 machine (with poorer specs than yours), and that just required, as I suggested above, going directly to MS.