Unless your organization, after wasting a year and tens of thousands of dollars on 5.0, has implemented a SOP to never use the x.0 of FreeBSD.
Frankly, if that's the lesson you learned from FreeBSD 5.0, I don't know that there's anything I can say to help you.
A more appropriate lesson to learn from FreeBSD 5.0 would have been "don't use releases which are cut from HEAD and announced as being for 'early adopters'". The FreeBSD 5.x stable branch started at FreeBSD 5.3.