I hate hi-viz tabards.
However, they have their advantages when you're doing a walk-round on a wet night as opposed to during the day in brilliant sunshine.
The luminous strips help at night when visibility is reduced. But why do we have to wear them on a CAVOK day?
By the way, the ones in BA have the following written on the back in red: "
DO NOT REMOVE FROM AIRCRAFT" Therefore, if you can't remove it from the aircraft how are you meant to do your walk-round in it?