I did not completely answer the first question.  The dual ported cards do
not perform as well as the single ported cards either.  We discussed this
with SUN when we decided to go with the PCI single ported SUN provided
Qlogic cards.  Basically, the chip that is on the card can really only
support about 1.5 equivalents of FC throughput.  The dual ported cards are
for failover to a different switch and connectivity and when you are short
on slots.  In no way should they be considered a replacement for dual access
to a LUN versus two separate cards on different IO boards (in SUN).  If the
card fails both paths are gone.

Again, this is a performance issue.  Solaris just like other FC attached
machines will scream if you put the PCI stuff in.

What Eric says, depends.  Yes, you can not do persistent binding of WWPN/LUN
to a controller/scsi device so that each LUN is presented to the system with
the same SCSI id.  A SUN machine walks the bus.  So, it really depends on
the device.  If each LUN/drive is a different WWPN then you have the
problem.  But, if it is like an IBM Shark where each LUN is presented with
the same SCSI id and a consistent WWPN, then you do not have the problem.
As I say, it depends.  I only have experience with photons and IBM Shark and
am speaking from that point of view.