I disagree with this.. I mean, yes slow and early is fine and good thing IMO. However with a machine there is no lead up (Pitchers sequence before the ball is released). So even if the hitter is slow and early, their timing is messed up.. they have nothing to reference, no wind up, nothing. You can ride the rear leg forward, but you still need to get that front foot down/heel planted.. and this is the part the hitters rush and force in order to be on time. So being slow and early does not resolve timing issues when hitting off a machine. You can still be slow and early and rush barrel delivery sequence when hitting off a machine. Like somebody else mentioned, the ball disappears and all of sudden it's rushing towards you.
Additionally the trajectory of a machine ball is different than a pitched ball... I prefer front to do front toss any day over machine fed. Game speed can still emulated in front toss... the only issue is distance
You can simulate the pitching motion while feeding the machine. Hold one ball in your left hand by the chute. Hold another ball in your right hand. Go into a pitching motion with the right arm then let go of the ball with your left hand when the right reaches it.