The main difference in my experience (I am both a FreeBSD and OpenBSD user) is in syntax, not functionality. It's not as if FreeBSD is shipping a strangely vulnerable version of PF. I believe it's possible also he may be referring to multi-core PF which last I heard was still a ways away in FreeBSD.
Multi-core pf landed in freebsd 10. There are further enhancements in the pipe, like a better hashing algorithm, planned for 11