step&direction vs analog

I am redoing motors and drives and electronics on a 4 axis lathe, I have it wired as step and direction but as i have a 7i77 and a 7i76e on it, I can do either step and direction or analog.  Step and direction is easiest enough to understand (thats why I chose it) but am wondering what is the best and most accurate method of controlling ac servo motors.

The gantry mill that i built runs on step and direction and runs accurate.

If any one that is familiar with analog and step and direction has a reason or preference over one or the other I would like to hear it.

Thank you

Thanks for your advise. I likely will stick with step and direction as its already wired that way, just wanted to check and see what was better.

My drives are Lichuan A4 series AC servo drives (chinese). The guy I know that has already redone a lathe like mine has same drives and he went analog. I just don't understand how the analog is controlled, I can only assume that it does it like a frequency drive only it holds it to the encoder count.

I had some extra drives and motors you could have played with but i recently upgraded my mill to AC servo and used them. I need to get more so I have a spare set being as I will have 8 of them in service.