Thanks for your insights. I have a USB DAC, so I chose a Firewire HDD. Last week, I added a 5v linear power supply to my DAC (EMU-0404) and the difference was huge - my Woo certainly liked the extra attention. This now has me thinking is there any gains to be had if I replace the switching adapter on the HDD with a linear supply? Or moot in the same way the quality of the USB/Firewire cable wouldn't matter?
I got the Mini - plugged it in to make sure everything was working and then immediately ripped it apart to install the SSD and RAM. So I'm not much help there? The SSD install was not for the weak hearted. The only things I didn't have out were the PS and DVD drive. I recommend puting the HDD on whatever bus you are not using for the DAC. Since the Duet is FW, I have the OWC Al-Pro mini on USB. I will move it to FW when I get the Wyred4Sound which is USB (or Toslink).
To date: 8 GB RAM for the mini coming Wednesday from OWC. Have Pure Music 1.72a; Firewire HDD and unnecessary services disabled. Also, looking at 40 GB SSD possibly next month. Did you add the RAM & SSD one at a time or at once? How would you determine each of their improvements individually from stock? Small, moderate or huge gain?