I went with SFS for the System and Work partitions and used a spare SSD formatted in ICE. ICE has been very reliable thus far. I'm using it for large movie files. Interestingly I had to use a USB device to move the large files over, SMBFS stopped copying at 4 GB.

I was a bit surprised that a lot of HD content doesn't play smoothly with mplayer. Using a PowerMac 2.3 GHz, SSD, and a X1950 Pro (AGP), I would have though more HD content would have played better. Even dug up VLC for Morphos and that didn't help. Would upgrading to a newer/faster PowerMac make a big difference for playing movies?