I use Vantrue N2 and it works well. Quality is good (better during the day time.)
I was involved in a hit-and-run where the other driver ran away from scene of accident and after two months of back-and-forth, his insurance coughed up 100% of the damages. And that happened because I had video evidence showing it was their driver who hit my car. So my dash-cam has already paid for itself many times over.
Capturing license plate is not a problem during day-light, but can be tricky at night time...though not impossible in many scenarios. But at the end of the day it is better than having nothing at all. Go for it.