The pfSense project http://pfsense.org/ which I use in my own router - https://medium.com/look-what-i-made/84152c1476d0 ) uses FreeBSD for the stable and robust packet filtering option provided by BSD's pfctl.

I've been under the impression that Linux's packet filtering options weren't as capable as BSD pf in years past but I know that, particularly as of 3.0, a lot of work has been done in this area. Would be worth researching but I haven't done it yet.