This is a nice idea, it's got some great ideas... However, there are a few things it needs before It will fit my criteria as being something I must have.
First, it needs a text-file output form, where it will dump hierarchical output in .txt or .rtf files. I want to be able to put comments on my listings without first resorting to hardcopy...
Second, things tend to get cut off in weird places in the .pdf output. Most noticeably at the top, just below the headers.
Third, some of the columns aren't needed for some things... i.e., it would be nice to be able to remove columns, like the File Kind one...
You might be locked into this format by the method used to print it, but in most cases the headers and blank scroll bars are just annoying.
And for the printouts, it might be nice to also have the ability to change typeface.
Another feature that might be worthwhile is to enable drag and drop of the directory to print. On projects, sometimes you just need to print out a specific folder or two at various stages, and it would be easier just to drag and print.
Sadly, without the .txt output, this has too severely a limited function to justify it's price for my uses. As for directories on projects, it's easier to cmd-shft-4, select, couble-click the .png and press cmd-p. It doesn't look as clean, but it's faster, free, and for me has the same functionality.