Personally I have a rather prolonged pause at the cue ball and again at the back of the final back stroke. I was taught that it served several purposes. Firstly is it gets "more consistent" action, especially at slower speed shots because a pause at the back of the backstroke forces you to accelerate through the CB. It also helps with speed control too. This could just be me since I've always had 2 pause phases so anytime I don't pause I'm not used to it and my speed control suffers.
A lot of snooker players have a very noticeable pause and I was told by one they use it at the end of the back stroke to give their eyes time to adjust. They look at the cue ball all throughout feathering the CB, then draw back, pause, eyes switch to OB, then they push the cue forward into the CB. My eye pattern works quite similar to this and it does really help if you have nothing moving in your line of vision so your eyes can adjust to either the OB in my case or CB in other cases before you strike a ball.
The pause at the start of the final back stroke I was told helps with checking you are aligned in the shot line. Its easier to check where your cue is aligned if its stationary rather than moving back and forth. It also helps you pull the cue back straight along the shot line too. These differences maybe very minimal to some and huge to others but its better to have a minimal advantage than none.