Yes! The foot switch is a must have for my work flow. It's useful in several ways:
1) Manual punching in, of course
2) Practicing a part or passage prior to recording a take. I can sit somewhat away from or not facing the DP and use the functions mentioned next to work on a part over and over and work the transport functions with my feet:
3) General transport duties... meaning using it in place of the start/stop, rewind to last marker, and record buttons (you can assign the button functions in the DP "Preferences" menu). This can also preserve the life of those buttons that get high mileage otherwise.
It does require batteries to operate - but I just checked mine the other day with a tester and they are still strong after several years of use.