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.
I think the long-standing impression left by 5.0 (despite carrying explicit warnings about being appropriate for early adopters) carries a good lesson for us: this sort of lore is surprisingly sticky. It doesn't matter that 5.0 was very much an anomaly that wasn't repeated, and that recent .0 releases were very stable. I suspect end-users like John are going to avoid .0 releases for as long as they use FreeBSD.
You're probably right, but that doesn't mean that we shouldn't point out at every possible opportunity that 5.0 was an anomaly and was clearly identified at the time as being an anomaly.
Maybe we can't convince John to unlearn his wrong lessons, but I'd like to avoid having him teach those wrong lessons to everybody else.
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.