An extended arm as shown in the photo above is fine for controlled shooting i.e. skeet, trap..however, in the field I find it an impediment at a quick swing. Locking or semi locking your swing/pointing arm greatly slows you down. This I experienced in lay down goose blind where younger, more agile hunters were up and on the bird before me. I switched to a Citori with 26" barrels and began to even up the score.

Nothing is foolproof to a sufficiently talented fool.