Hi.
Used the NiZn cells by PowerGenix for two years now, and they are total garbage, unreliable, unpredictable uniformity from one to another of the same batch, and self discharge at an unacceptable rate.
I also had good expectations, but now I do not recommend them at all. Their web site and specifications is full of hot air, if they are still in business.
Edited - added: And I have tested them in fast discharge items, low rate discharge items, camera, toys, flashlights, alarm clocks. Ended with a LiIon 16850 feeding a camera by its external power jack for true reliability.