I use my brain to connect the dots that my system remembers for me. In my opinion it's not necessary to take the effort to "link" actions and projects within the system. It adds overhead and isn't nearly as fast as my brain. I also find value in having my brain connect the dots during reviews because it refreshes my thinking about my commitments.
Originally Posted by DavidH
A system with the ability to link actions and projects and reference materials together is far more cool than it is useful. The best GTD system is the simplest one. If you're set on having linking ability within your system then you're stuck maintaining two systems. If you're ok with just managing reminders of your outcomes and actions then you can consolidate your reminders into one system (preferred).