iOS 8.0.2 - Black Screen After Startup?

Same thing here in my iPhone 6 plus, numerous times.

 

Same with my 4S. Plus it seems to take an extended period of time to actually power off. It freaks me out a little when I have to power off and back on because this startup makes me think it's locked up and unusable and I just spent two days restoring my phone after the original iOS 8 upgrade failed and sent it into recovery mode. Don't want to have to go through it all over again...

 

I had some time to waste trying things to check out this nagging issue on my 32GB iPod Touch 5. It takes an extra 40 seconds to restart my device because of this issue. The issue occurs on: iOS 8.0, 8.01, 8.02 and 8.1 beta.

First I made a backup to iTunes and copied the backup file.

These steps failed to correct the problem:
Set airplane mode, restart.
Logging out of iCloud, restart.
Logging out of iTunes, restart.
Reset network settings.
Reset all settings.

This “fixed” it:
Erase all content and settings.

This “broke” it again:
Restore backup (from iTunes)

So it has something to do with my apps and/or data installed on the iOS 8 device. On iOS 7, this issue did not exist.