Boron EN-Pin vs Deep Sleep

I am using a low power PIC to control the “Sleep” on the Boron. Should I use deep-sleep with wake up pin or ground EN pin. What will have the lowest power usage? I will power the PIC from of the batt pin.

What does the EN pin shutoff vs deepsleep?

Any input would be great.

Thanks

The EN pin shuts off the entire device.