I was afraid YT would screw up the videos, as always, and it did. Believe me, there are A LOT of differences between the originals, including the Da380, and the DOD's/Shadows. If you want I can upload the original files to Dropbox or Google Drive. I have some other videos I shot before on another location where those differences are more noticeable.
What I can say is that the levels of contrast are so high on the GT300W firmwares that when the sun is reflecting on the number plates you can't read them and every reflection is captured by the camera. The DOD's are a bit softer but nonetheless very dark too. This wouldn't be a problem if they responded well or fast to light changes, which none of them does. Every shade is pitch black, as is everything in it, and in reality they're not that dark.
I did a driving test with the LS388W and it's a little bit brighter that the LS300W but not enough to be the chosen one.
The 3 originals, on the other hand, "see" things much closer to what they are in reality and are quicker and more responsive to light changes. The downside is that the two "real" originals have lower VBR but then there's the Da380, which has the same characteristics of the originals but with higher VBR.
The one I would like to keep using, if it wasn't for the contrast and darkness issues, is the DOD LS300W 2013.0328. With an overall bit rate of 16.5 Mbps and two audio channels (I know they're just a double mono, not real stereo, but the quality increase is very noticeable), it's all I could ever ask for.
But, and there's always a "but" in all "perfect" things, it reduces a 32Gb card capacity to just 2 hours and 56 minutes, which means that if I was to use this firmware, I'd have to buy a 64Gb card. I know the manufacturer says the camera only supports cards up to 32Gb but there's someone out there who successfully formatted a 64Gb card to work with these cameras.
I'm sorry the videos didn't show the differences as I would expect them to but I hope this report will help people decide which firmware to use, in case they want to give it a try.