Gold if you compared it with what? I think that Arch wiki is superb and have a lot of more information for the experience user than the FreeBSD manual which is excellent only for the first approach.
The Arch Wiki is superb, indeed. Let's call it platinum. ;-)
My issue is that if volunteer driven projects like FreeBSD, Arch Linux or OpenBSD can provide very high quality documentation, I expect commercial ISVs to provide documentation that is at the very least that good. Instead, documentation is often either missing entirely or very bad. Or they have the audacity to charge you extra for a manual.