beamer
An instructional background really sharpens your stick and rudder skills and airlines appreciate this. This ultimately increases your mental capacity to absorb other stuff. My FI background really helped when I got my first job on a turboprop. I had more confidence in my abilities when it came to hand flying the aircraft from day one.
I was talking to a friend of mine who is a skipper on a regional jet. He said that even if he does not know the background of the guy sitting beside him in the right hand seat, he can always tell a ex FI as soon as the autopilot is disengaged.