I was recently on a four day/night trip in Central Kalimantan on the island of Borneo to see orang utans in the wild. I took my Fly360 HD with me. The problem was I was on a small boat alone with two crew members and we stayed, ate, and slept on the boat with no connectivity or electricity for four days. Without additional AC power, my Macbook would not allow me to download my content. So, I was stuck with not being able to download content from the Fly360 HD. If there were a micro SD card in a model, I could have done that. I had a Go Pro Black with me and could do that just fine. Most people probably are not without an actually AC power connection for four days. Of course the new 4k unit has more memory, but I am not ready to spring for another pricey purchase unless there is a way like a memory card that one can switch out when on extended adventure travel. I just spent substantial bucks on the Fly360 HD at full price in March and am not willing to do it again so soon unless they arrive at a significant trade in deal. The waterproof feature is not important to me. So, there needs to be a model with a memory card that is not waterproof.
My macbook laptop had battery power, but would not let me offload files from the fly when just relying on battery power of the laptop bus. I did have an extra power stick with me to keep my cell phone charged to work with the 360Fly.