I would think that you'd want any touch on a big board instead of the 620 (I prefer fob on any size board). I believe any touch on a smaller board restricts play.

Playing any touch on a 620 would be in the Defense best interest. I was playing a dude from another league who plays on a Big Board Front of Base. I asked him why the small board and he replied this is any touch. So with that I notice all of his league mates doing the same thing. When you play front of base you can spread out and have a better run game. I prefer to play any style on a Big Board.