What I usually do when I run out of space is search the drive for folders over a certain Megabyte size... say 25MBs. Then I sort by size and I can selectively delete the larger files...

Right, exactly. That's what this utility does. Only it shows it to you in one step, in one clear screen, with a super-easy-to-navigate interface.

The thing that this utility helps with is the first step: "Search the drive for the big folders". This utility shows that very thing (which folders are the biggest) in one step, automatically. I don't know how to do that in one step from Windows Explorer or from a batch file. The only way I know how to do it is with a third-party program like this one.

It looks awfully complicated.

It's really just the opposite. It's very simple, actually. The interface looks strange at first, but once you understand it, it's so simple and clear, and presents you with exactly the information you need.