The product itself is really nice, solid construction, designed well with screws in the side of the front half to make smaller or larger and a screw on the back to shorten.  Even with the minor tweaks though, the difference between the L and the XL size is too great and so it really doesn't work as well for intermediate sizes.  I have side 12 shoes, so the L is too small and the XL is too big.  When I use the L, the heal doesn't touch the heal of the shoe, but when I use the XL i have to compress the shoe tree so that the front and back half are almost touching.  Seems like this could easily be fixed by making the L a little longer (it's on a spring, after all) or adding some intermediate sizes for a little better fit.

Wish I could give this more stars.