Charlie,
The question you ask ranks right up there with asking what type of primer shall I use. The answer is that builders do both methods and they both work.
I fall into the camp that ran everything back to the forest of tabs on the firewall. Yes, it meant I paid a little weight penalty to running the additional #2 up front.
Many builders install conduit starting at the aft edge of the baggage area floor, then transition to the side walls under the rear seat. Mine end just forward of the spar. You can find photos on my build log. I pulled a 3/4" and 1.25" conduit to each side, as well as another 3/4" to under the rear seat where the comm antenna are located.
The instructions for the Van's electrical system are floating around on the Internet. I found them interesting as in it gave me some ideas on how to do a few things. However, it will give you a very simple, basic, working electrical solution. Most builders tend to install an electrical system that is more robust than Van's design like Nuckoll's Z-14 or. Vertical Power solution. I installed a dual bus solution using a VP/X.
Local attached grounds have been used for ever in aluminum aircraft. That strategy is well proven. I felt that the single distribution point of grounds was a better solution for me. There is no correct answer to this discussion only the answer that best meets your needs.
Bob
