You are correct, but to be clear, that's not what I mean when I said that "you can swap out mulitiple iPod Nano's". What I meant was that since 7th Gen iPod Nano's have small space size in nature, once you use up all the space on one 7th Gen Nano, you can swap out a 7th Gen Nano that doesn't have music you want with one that does. It's pretty easy to fill up a 16GB Nano with AAC 256bit files, so in most cases, you'd need an additional Nano, or maybe you're Nano dies and needs to be repaired or replaced, which ever the case, my set up compliments those situations :-) But like I said above the corresponding picture, it's not advisable if you don't want the set up to be permanent. My set up is clutter free of slip mats and thick rubber bands, but comes at the cost of restricting the set up to 7th Gen iPod Nano's. I personally love it so far. It's just so convenient and portable.
This is the first time I've seen anyone do this, so naturally, I'm expecting this method to meet much criticism and speculation. But I stand by it, so I'm willing to answer those criticisms :-)
Haha, I hope you knew I was just playing around!
But anyways, many people, including myself, have had a similar alternative to a band-free rig, with the use of removable Dual Lock. That stuff holds strong, but also can be removed easily. You might want to have a look at that:) It's also not permanent, hence less problems.