Hi Mike,
One school of thought says that leaving the B2 powered at all times will improve the reliability - as for any electronic device. If you decide to do this set Screensaver - Maintenance menu - to 16 to turn off the display in Standby mode - this will extend the life of the OLED display.
I switch my B2 on and off each day, as part of my support role and have done this for over four years. I usually do the 'Save' routine before powering off - press and hold the Play/Stop button until 'Saving' is shown briefly and the clock is shown again before releasing the button and powering off. If the B2 is already in Standby (displaying the time and date) I just power off - which I do at the mains socket.
This makes sure the B2 is idle when power is removed and is not accessing the HDD/SSD or the SD Card.
Paul
Brennan Support.