rpinchbeck posted guide at viewtopic.php?f=61&t=23271
to switch to Debian Squeeze. I was running Freelink but flashed back stock by wiping the partition tables. From that starting point the guide is rock solid. I bricked it a few times trying the procedures for the Pro, but this one for the Mini works on the Pro. There's issues with the LED's and the switch, but that applies to any non-stock build.
He also posted a kernel build script here viewtopic.php?f=61&t=23793&p=146815#p146815
. If no previous config is available, the script pulls your running config from /proc/config. Once it drops into menu_config, you could just hit exit, save and let it build a new kernel right there. Or enable any options you need.
I still haven't decided if I need iSCSI. My media box can use the Duo via NFSv3. NFSv4 could be fun, but could be overkill with having to get uid's sorted. iSCSI mounting it would make all that go away.