the PF available on FreeBSD is woefully out of date. If you use FreeBSD regularly and don't mess with pf, learn ipfw. it is quite powerful and much more performant.
I'm surprised this is the case, since pfsense is a very capable FW built upon the pf version on FreeBSD. I've been running it for years with nary a problem. Would you say the outdated version of pf puts people running pfsense at risk?
Everything he said is true and I know this for sure. But I like PF so much and even the stripped down version of FreeBSD feels awesomely good. You're in no danger what-so-ever. OpenBSD's version of PF has loads of advanced features and way better performance but you'll only notice these things if you need an (very?) advanced configuration.