IDE-CF adapter definitely work as an install destination as I have one connected on the primary channel of my Fast-ATA controller and the OS4 installer can see it fine but I have not yet tried actually installing to it as want to check the the cooling on my BlizzardPPC before running OS4. As I have heard a number of people reporting heat issues when running OS4 and I don't want to take any chances with such an expensive and hard to replace bit of equipment.
