I bought the unit directly from Vaistech as they have a 'group buy' going on until the end of October I believe.
I'm still trying to decide which emulation mode I want. 'Simple' mode allows me to control the iPod from the iPod itself (for example, choose the playlist) but doesn't display track information on the headunit whereas disabling 'Simple' mode allows me to choose the playlist as well as other functions from the headunit itself. Given the limited display capabilities of the 4th generation system (2005), I'm probably leaning towards using the 'Simple' mode to use the iPod itself to choose the playlist. I don't really need to see the track information from the headunit.
One item that is a little confusing right now is that the application guide from Vaistech shows the unit emulates a CD changer for the 2005 RX and I have followed the programming instructions to set the unit up as such. However, when I choose the mode on the headunit, it shows as MD. This would actually be preferable as the CD changer mode limits playlists to 99 entries while the MD mode allows up to 999. So I'm hoping I can use MD mode. I'll be reprogramming the unit this weekend to MD mode to see if that works.
I'll also attempt to route the iPod cable under the carpet and into the center console for a cleaner, more secure installation this weekend.