I like the "ref on the run" chat. He's following the ball, but sees something out the corner of his eye, says to the TMO "check that", and either gets told it's nothing or something happened that needs attention. If he has to wait for the next break in play to stop and ask the TMO, it's too late or else the teams stand round for two minutes while the TMO reviews. How is that an improvement?
The other advantage of the ref on the run is that quick conversions cant negate the TMO.
I'm amazed they didn't do away with the quick conversions thing over the summer. Obviously quick conversions should still be allowed if you're trying to save time to get back into a game (though in that case the team who are winning just walk very slowly back to the halfway line anyway) but they shouldn't be a means of getting away with a dodgy try. If a ref sees a team trying to go quickly he should just blow the whislte and call time off.