I bought this a couple of months ago and have given it a really good testing. When the GoPro Hero 3 came out, my main gripe was the battery life. So I went and bought a Battery Bacpac. That was good, although it bulked out the camera and added noise to the audio. However when I found this deal on Amazon I was a little wary at first, yet I decided to go for it.
I was blown away with the quality of all the components, the packaging was good and the branding is great. I like how the power switch logo matches the GoPro's.
Quality: Excellent. The batteries fit very tightly into the charger, but that's fine. A bit of jiggling and they charge well. The battery build quality is hard to differentiate from the genuine battery, although the tape tab on the back is a little looser.
Performance: These batteries perform as good as genuine battery in field tests. The charging is quick, and the in car charger works just as well.
Overall, for what you get this is an absolute steal! I no longer have to worry about running low on battery, and always have spare with me.