I bought a Garmin NuviCam in 2015. Will never be without one now. I have also bought two of the small dash cams, but they are no where near as easy or nice as the Garmin. The screen is too small to review anything and the controls basically suck.
I was so pissed at myself, I went to transfer my Garmin to my other truck in preperation for a trip in it, and dropped the damned thing, cracking the screen. It still worked but the camera controls were dead. Thats when I went and got the other camera. It took me a while but I did finally find a replacement screen through alibaba, and was able to replace it. MesoHappy!! We are going to Florida this weekend and I get to use my Garmin again. I prefer it over the newer built in Nav, and I can use Basecamp to plan out trips and upload them to the Garmin.
So if looking for a Dash Cam, look at two things, HD, or video quality, and video controls. The easier to work, the clearer the picture, the better it will be. What I like about the Nuvi cam is that the GPS coordinates and speed are on the video. The speed can be turned off, but when you get pulled over for speeding, when you are not speeding, or pulled over for blowing a light or sign when you didn't, case closed.