Love this thread!
I've got a couple of old iPods I'm thinking of upgrading, an iPod Mini 2G and an iPod Video 5.5G. I think I'm going to go with a straight CF card upgrade for the mini, but I'm not sure about the iPod Video. It's one of the thicker 80GB models. If I put an SSD ZIF drive or a CF card in there, could I replace the old 80GB back with a 30GB one to thin it down? Or even an 80G 6G back? From what I've read, the 5.5G and 6G have the same dimensions; I realize that doesn't mean they'd be compatible, but I don't have one to physically compare. I'm guessing maybe the ports between the thicker and thinner models don't match, but I can't seem to find that information anywhere. Has anyone replaced the back panel during an upgrade?
I have exactly these two iPods (well, the 30GB one instead of the 80GB) and have modded both to 128GB of storage. The Mini takes a straight CF card, and I used the Tarkan board with a SD-to-CF adapter and a 128GB "full size" SD card. I replaced the batteries on both and stuck to a 30GB compatible battery for the Video. Playback time on both seems similar, but I have not done formal tests.
I also amp mine with line-out docks (LODs) to portable amps. You can see them in this picture linked below. The Video is in a yellow-trimmed case and is connected to a FiiO E12, whereas the Mini is the silver model and is connected to a FiiO E17.