Any insight on why we'd need to disconnect and reconnect the power cable before install of 3.0.1?
Not specifically just for this update no, however I include it as part of all tv update procedures. Pulling the cables will reset certain system management hardware in some systems, whether this applies to the tv or not I don't know because we don't know much about the gubbins inside the device.
If you're interested my update procedure is:
0. Check for itunes updates and update if available.
1. Perform a sync of your library.
2. Remove ALL cables (for around 30 seconds)
3. Swap HDMI cables for component were possible.
4. Go to itunes prefs and check 'Prevent...from auto syncing'
5. Restart the tv.
6. Download and install the update.
7. Restart itunes.
8. Re-enable autosyncing in itunes.
9. Manually resync your library if autosyncing hasn't already done so.
I've never had any issues after an update, there are some here who put this down to luck, that may or may not be the case, I don't know, but no point in breaking a lucky streak by changing my system.