I took this camping on the Nibrara river last weekend (brand new, just got it)!
Go to bottom for TL;DR (5 stars overall).
The panel itself is sturdy and waterproof.
With occasional partial cloud cover, this charged my Jackery 300 from 10% to 100% in 6 hours.
Unlike other Jackery models, it does not charge non-Jackery devices by itself (BUT it will charge the generator while the generator charges other devices).
It does not fold (I would prefer a foldable joint in the middle for increased portability, even if the total surface area had to be increased some to maintain the conversion efficiency).
The case should be a bit sturdier than it is; the cargo is precious, greater wind-resistance would improve the reflective charging slightly.
The cords are durable and handy and have nice velcro wraps.
Setup is super quick and it is easy to secure with a cord and lock if you are leaving it for a few hours.
I don't know exactly how much more efficiently it charges compared to other models, if at all, but I am definitely satisfied by the charging speed.
TL;DR
Overall 4.5 to 5 stars:
A seriously efficient, handy, and durable piece of technology that is visually pleasant, but could maybe use some practical tweaks to design or additional options.