I purchased the Viofo A129 Pro Duo with the Cellink Neo battery and HK3 ACC Hardwire kit, including an extra CPL filter for the rear camera. The video quality of the cameras are quite good. I've had four others made by Rexing and the Vantrue X1 and X3. The feel of these cameras are substantial, feels well made compared to others I've had and the mounts really hold. The CPL filters also appear to be made from quality materials and the wiring harnesses are excellent.
One of the features that I really wanted to take advantage of was the Auto Event Detection, while in parking mode. This feature buffers several seconds of video in memory ahead of an event so that when something does happen, it commits what is in memory to the microSD card and you don't lose the initial impact of the event. Otherwise, when nothing is happening, the camera is always watching but it is not writing to the microSD card. A great feature, but it does not work if you use the included GPS mount...what? So you have to decide, do you want GPS data or do you want Auto Event Detection; you can't have both!
I have sent a request to the support team to see if they can submit this as a future feature enhancement through a firmware update. I hope they can make that work, but for now this is why I can't give this a five star review.