"Scott Lurndal" wrote in message
news
A drum sander and a planer functionally overlap, but while
there are tasks suitable to both, many tasks are only
suitable for one or the other.

One cannot reasonably replace a planer with a drum sander,
particularly for surfacing roughsawn lumber in any significant
amount.

What is a "significant amount"? I've done at least 1000+ board feet with
mine. Not all at once, just whatever I needed for the current project.