I bet you also get a much better result as this eliminates 2 sources of surface finish imperfection. A more constant feed rate improves the result. Turning by hand introduces up/down and side to side forces on the slide that can deflect the tool path.

The hand wheel on my slide is held in place by a hex nut. I used a socket in my variable speed drill to do a similar thing, but I could not use it to back up as it loosened the nut.