The most unreliable part for me has been Windows (10) crashing when it takes an update from the mother ship. This happens every few months on one or more of my BI systems. Sometimes, rebooting fixes things. Sometimes, I must do clean re-install of the OS and start over. I suppose one could disable automatic updates and only 'catch up' once in a while when you can afford to take the time/risk to do so. I know that's not a very glowing endorsement, but that's been my experience over the last 3 years. I could be doing something wrong, but I dunno what that might be...