Full control seems to be more of a "black magic" than a science.
While riding, you can only switch between songs (short press), or depending on what mode you have set, albums or playlists with the long press.
While stopped, using the mode button, switch over to the ipod, then long press, and you will get a menu where you can select playlists, albums, artists, etc... Where the black magic comes in is that the menu is 3 or 4 layers deep, yet the display only shows 2. So many times I have selected an album, only to find I did it wrong because I didn't move over to the 3rd layer to start the album playing.
BTW... I'm probably not the best source, as I'm not a fan of iCRAP. I only have the iPod for the Spyder. If the Spyder ever goes away, iPod probably will too....