I have it turned on with excellent results on an IPC that I've been
running for over 8 months.  I've had terrible results and have had to turn
it off on a Sparc 1 I've been running for 4 months.  Unlike sync/async
bnegotiation, the driver doesn't seem to automatically turn off
select/reselect on the older chips.  Given that and our desire to work out
of the box on a variety of hardware revisions, I vote for leaving it off in
the GENERIC config file, at least until we have a driver which is
reasonably good at working around the variety of bugs in the various SCSI
chip revisions in the sundry Suns in the land.
-Brian