How accurate are your voltages?
The voltages are certainly not perfect, but useable by me. the 12V tie puts out ~11.75V solid, I haven't been able to do anything to it that have pulled it much lower.
So where does the power in come from and you did not show or mention that?
I guess I failed to mention how the power gets into the box... I just have it hard wired through a three-wire cord, maybe 6 feet long. It allows me to reach an outlet in all the spots I need to use it. So it puts a switched outlet on my desk where I don't need to move shelves and rearrange the house to get at.
After using it for a few weeks it has turned out very useful, although one catch I've found is that the PSU has some sort of "short-protection" circuit, so you have to be sure to balance your circuits, unlike the 7805's that you can beat the livin daylights out of!