im not sure about the difference in usage with a deck but the reason they came out with new ipods is to make better ipods... i dont have a brand new one i have what is now called the 30g iPod classic... the newest have better screens but if you are controlling from the deck that wouldnt matter... all i can say is the touch is a waste of money very little storage and a huge price tag. and get twice as much storage as you think you'll need... i was origionally going to get the smallest nano cause i didnt think id need room but when i went shopping for my ipod was right in the middle of the change over and i got a 30g for $250 at the time i think i had like 2gigs of music i now have over 8 so had i bought a 4gig ipod id be screwed hahaha