Very informative, thanks. I noticed that my HDD (with my settings) spins down, but also that it spins up after a while, maybe after an hour. With the old 1.0.4.6. firmware and the same instructions it really spun down 'forever'. I have both mt-daapd and Twonky running, and both are told to not update anything if not asked to do so. So I think now something else must sweep its tail now and then.
I guess we will find out some time.
Again, thanks for your long answer.
According to
http://wl500g.info/showpost.php?p=45110&postcount=5
the Asus consumes about 5 watts to let the HDD spin. Now I'm curious how much power is saved with your settings. Do you know that?
Marc