The only difference is the bands. Due to several complaints about our first bands, we had to redesign them to be sturdier and durable. If worn correctly, your band will keep your core safe (How to Wear Moov Now™ Correctly).
We replaced the bands for our backers as well. Unfortunately, it seems like some resellers are still carrying the old bands and selling them at a discounted price. We do not recommend purchasing devices with the old band as it is likely that your core will get lost.