I don't use this kind of case every day but I do use it occasionally when I'm going out somewhere where I know I'll be using the camera and GPS a lot (e.g., road trips, festivals, fairs, theme parks). It's especially useful for the holidays.
I've been using ZL battery cases since the days of the Galaxy S4 and I must say that this is the best design yet in terms of build quality, build materials, and compatibility with glass screen protectors.
The texture of the case feels dense, durable, and high-quality. Fitment is also perfect, with all the buttons and ports correctly aligned and easily accessible. What made me the most happy was that there were no issues with my glass screen protector -- no lifting, no peeling off in the corners, and no undue pressure.
I also liked the performance of the cameras was not affected. The same can't be said for the audio, however. The audio became a little bit hollower sounding and a little muffled. The difference with and without the case wasn't dramatic but still noticeable.
In terms of battery charging speed and battery life extension, I'm totally satisfied. Using the GPS for hours and taking hundreds of pics and tens of videos got me through a 12-hour day easily. I think most people will be just fine with this 5,000 mAh battery case and can skip the bigger and heavier 8,000 mAh case.
Here are some pictures I took:
Some people like seeing number scoring and I rate the case a 9 out of 10. One point is deducted for the slightly lessened audio quality.