How to back-rev?

[John]

I think I may have been too eager to go to Major Release 5 of FreeBSD.
I'm having a lot of trouble with my laptop - with my WIFI cards
freezing the system, and trying to make the swith from XFree86
to Xorg.

Can you use the /stand/sysinstall "upgrade" to go backwards?  What
about filesystem formats?  I know that FreeBSD 5 added some really
cool filesystem capabilities, like snapshots - but did that make
changes in the filesystem format?

Thanks!
-- 

John Lind
john at starfire.MN.ORG