I have been using a shark with ipnat to support an overlay internal
network (i.e. both external and internal on same ethernet, which isn't
as secure as it could be but is ok if I trust my service provider and
dsl modem). It has been running fine for about a year (using one of the
1.3 snapshots), current uptime is 132 days. Im thinking about moving to
1.4 (and enabling the new getty/pppd so I can either login or PPP
connect my PalmPilot on the serial port), but Im currently caught in a
"if it works don't fix it" dilemma! I use a ZIP for the filesystem and
memory filesystems for log files etc. Once I hit cron over the head to
reduce "housekeeping" the ZIP only spins for a few min a day, the rest
of the time the system is silent. Doing FTPs though the shark/nat I see
full DSL speed transfers (416kbit/s).

As far as the PCI UMI goes, my recollection is that there was a little
testing done from the OpenFirmware (using a real kludge to link a UMI to
a regular PCI slot) but nothing was done from NetBSD. Rev 1 boards have
the "PMC" PCI Mezzanine Connector and I recall reading the config info
from a DEC PMC ethernet card on a rev 1 that had a couple of patches
(that went in to later revs). I don't think the VIA PCI bridge will give
great performance (and I don't think DMA from it was ever tested).

Mark