I think I would like to see scrums back with less seconds on the clock, for me their has been a gradual creep of delaying the game anyway under the new rule, the ref asks the team where they want to play the ball, players have a discussion about it and slowly walk to the new PTB position. By that time the opposition have set up a 13 man defence and have had at least a 20 sec rest, also some players see the opportunity to have a lay down to claim injury.