BSD is real Unix, Linux is a foreign clone that's been picked up in the US by IBM, which despite being a much bigger computer company hasn't had the same level of success. Mainly because the license is different, which allows Apple to keep parts of the O/S private, so their competitors can't use them in other products. Conversely anything that goes into Linux can instantly be used by competitors, hence the best features almost always get put into Linux last.
I wish we could all get our terminology straight to avoid confusion. I hear too many “Linux == Unix” comments. Then we need to get straight what “Unix” is. Are we talking codebase, functionality or trademark (certified)? If we’re talking codebase, that’s Novell’s (sorry SCO). If we’re talking functionality, that’s a lot of operating systems equally, including Linux and BSD. If we’re talking trademark, only OS X, AIX, Solaris and HP-UX are allowed to be marketed as modern UNIX.
While we’re at it, I’d like to get rid of the term “Intellectual Property.” It causes and/or shows confusion in almost every thread I see it in.
It depends on what you define as "best features." Linux gets a lot of features before any commercial OS, but they tend to be the kind of things the geek-boys like to code for themselves. Popular features introduced by Mac or Windows -- especially support for new hardware -- are where Linux is necessarily playing catch-up.