> A really big difference is that FreeBSD is the kernel and userland together. Can someone explain the significance of this as the author seems to keep glossing over it. What's does he mean by saying they are "together" and what is the advantage of it?
The author might be saying that the FreeBSD OS is essentially treated as a single distribution that is both developed, maintained, and packaged cohesively by a single team, as opposed to Linux, where the kernel team (led by Linus) develops the kernel (and maintains/integrates associated parts such as device drivers and filesystems), other devs develop other utilities, and distribution teams pull together everything else (usually either a company such as Canonical or Red Hat, or often a team of volunteers such as with Debian.)
For the latter, it really comes down to a difference in philosophy: because FreeBSD is a single, cohesive unit, there's less room for differing opinions and variety in the mix, which can deliver solid results but with reduced "moving fast and breaking things" that sometimes result in faster innovative leaps that you might see on Linux. (But how much do you enjoy seeing your core infrastructure broken? e.g., this is also why Debian has three tracks - stable, testing, and unstable, to accomodate different levels of risk.)
(Your choice of operating systems may have nothing at all to do with your choice of governance -- but the solid, stable approach could be characterized as conservative and the move fast and break things could be progressive ;) personally, I like both at different times)