Overall, what I like best about FlexiTrace is that it does the job just the way I want to have it done, simple yet effective. As a user I have the impression that the developers actually USED this software. Although, I would qualify that intended compliment by stating that some "scientific/engineering" use and features would improve the product for that portion of the market (see my comments below).
As an example of 'usability' features, consider the "plumb-bob" tool. If you have ever scanned in an image you probably know it is almost impossible to align the image vertically and horizontally. This is especially true if you are working from a carelessly made photocopy that is slightly rotated relative to the paper edges. The "plumb-bob" tool in FlexiTrace solves that problem by simply allowing the user to draw a straight line on the scanned image that represents "true" vertical. The FlexiTrace software then rotates the scanned image to make the indicated line vertical, simply and effectively. It makes you wonder why other software that imports or generates scanned images does not have the same tool.
Bottom Line: -- If you need the digitizing features described above, FlexiTrace will meet and exceed your needs. It is a single purpose tool with some useful features that accomplishes the task of transferring graphical data back into numerical form.