The 5° measurement is worst cast. I have no cherry to break and you're coming across pretty defensive. I'm just pointing out that you can eyeball it and have results that are 99.6% as accurate as a $$$ tool.
So yeah if you can't eyeball 5° (or better) then get a tool that will do it for you.
When your first post is trying to pick an argument, instead of introducing yourself in the welcome wagon like most normal members, yeah, maybe I am defensive. When it comes to camshaft timing, I choose not to "eyeball".