I've used ealier versions extensively, and found it very useful (especially the ability to change file/folder names within the catalog for items stored on optical media). I don't know of a better program on OSX for cataloging large numbers of discs.
However, I find that the new v5.x interface is off-putting enough that I have been sticking with v4.7 for a while now. My biggest complaint is that the display within the windows is extremely inefficient, with tons of wasted space everywhere (huge indentation and tab values, large interline spacing, very large "header" area on all windows, unnecessary and undefeatable pane interface on the main window, etc). An additional annoyance is the fact that some key commands have changed or been removed (eg in versions up through 4.7, cmd-minus would navigate one level up, whereas in v5.x it shrinks the text & icon size).
To a certain extent, this inefficiency in the graphical display of data and window structure is endemic to the latest developments of OSX (which itself is a shame), but I think that even within those parameters, things could be greatly improved with CDFinder.