I have massive problems with both shutdowns and reboots. Open OH and take out battery only fixes the problem temporarely.
But 2 days ago i really took battery out for 1hour. Since then I didnt get one shutdown/reboot. We'll see.

Some days ago I got a care email saying they fixed two problems regarding shutdowns and reboot loops.
I'll wait the new update before sending my phone in if it still should be needed.