I think for me the part that makes me nervous is the unknown. The fact that I don't completely understand them. How do you know how many you need, etc? Do you replace batteries with them, or if you had batteries would you run them along with those batteries? Stuff like that. If you're replacing a battery with these, say you had a D7500, how many would you need to equal that?
I won't like, I saw this on facebook yesterday too, and I thought "hm xs power came out with an energy drink". You know like NOS did. LOL
OH RIGHT, Like none of you thought the same thing!!!