My understanding is that -current contains bleeding edge stuff.
As such, any machines running -current should be considered
disposable.  Here at Chez Casa (or House of Chez Casa when I
feel pompous), I have a FreeBSD box that was running 4.2 until
recently that has a big disk and is slow and pokey but faster
than the net and it serves NFS of home dirs (and often source)
and does mail and such.  I took a big jump and moved it to
FBSD 4.8.  But it serves the NetBSD boxes and OpenBSD boxes
that run -current.

Occasionally, the -current machines eat it.  Then I have a backup
with 'boot net' (sparcs) to save my sorry ass.

Filesystems are sort of a razor slide on that bleeding edge.
Those I expect to explode.  But that's why the FreeBSD utility
box is there.  Nothing fancy, just functional as a parachute.

Data loss on -current?  expect it.  Don't hope for it, but
presume it will happen more than never.