I was disappointed with the Dark Energy. I got roped in with the cool orange and camo coloring. I'd say 20 to 30% less efficient than my same size Anker. Of note just this past weekend at a baseball tournament someone was complaining about the DE rechargeable bank. Then one that has the solar cells on it.
Nite Core was close to the Anker. I thought though they were more temperature sensitive than the Anker.
Not sure if they are still around but I have a Rav Power that has been great. I am interested in the Nite Core and Anker is always a good option.
I had a Dark Energy that quit working after two years. Not worth the price.
I use Anker 20,000, 10,000 and 6800. They all work as intended. The 10k gets the most use due to its size and power storage capabilities. If they all got stolen today. Tomorrow I would buy two or three 10ks and run with those.
FWIW i just bought an anker 10,000 mAh for $17. weighs just under 9oz. tested it this week on iPhone 15 pro. first charge from 15% to full then ran my phone down to about 30% and only got up to 80% before the anker was drained.