A thousand times this. A working demonstrator of a useful idea that is honest about its limits is so valuable. Mover over most commercial code is garbage! :)
If only to help people who simply can't read academic papers because it's not a language their brain is wired to parse, but who can read code and will understand your ideas via that medium.
[EDIT]: to go further, I have - more than once - run research code under a debugger (or printf-instrumented it, whichever) to finally be able to get an actual intuitive grasp of the idea presented in the paper.
Once you stare at the actual variables while the code runs, my experience is it speaks to you in a way no equation ever will.
