I got the Vantrue S1 which is identical to the Junsun S590.
You can find my video review of it on this link:
Vantrue S1 review
It looks identical, It has identical declared features, but it has completely different firmware.
In Junsun S590 you can't record speed and geo-location as timestamp on video. It is recorded as data, but to see them, you have to use dedicated software (like Replay from NextBase - than you see all data and recorded track on the map).
You can't use Vantrue software to replay your Junsun recordings. Actually, you can but without recorded GPS track. Apart of that limitation, player is very slow in loading files, but maybe its not caused by Junsun videos.
Finally, you can not update Junsun with Vantrue firmware, or maybe you can, but the way how to do it is different from VanTrue firmware update manual.
For those who want to know some more about Junsun S590 than only what is quality of image on both front and rear cameras:
For first, GPS receiver in Junsun S590 is worse than in most of modern mobile phones (I guess there is no GLONAS nor GALILEO support), but its good enough to fix position. Unfortunately I found that my windscreen is blocking signal and in result I have problems with fixing position. Weakness of receiver/antenna is just partially responsible for my problems (satnavs works and windscreen is no problem for them).
Luckily, I discovered that I can get goof signal if I will fit camera somewhere on black painted area on top of windscreen (behind and around rear mirror). Tested this whole day and signal is so strong that location is fixed in few seconds, and accuracy is really way better than before.
On adverts you can read that there is dedicated app for iOS and Android. Nobody say that this app is really bad. Good news. There is no need to use any app but internet browser. After WiFi connection with camera is established - just open chrome, or whatever you prefer and in address bar type in:
http://192.168.1.254
In result you will see very simple access to SD card directory. You can download video files from there (there is also option to upload). Speed of download is not impressive - 450MB file (1080/30fps - 5 minutes clip) download in approx 7 minutes.
Another feature of WiFi and mobile application is live view from the camera. We can avoid using dedicated app with another app - like "VLC Player" (also on PC). When connected to camera, just open stream location with VLC; rtsp://192.168.1.254:554/ You will get nice stream.
All this can be done on any device, on any operating system - not only iOS or Android, so this tips should be usable for all trackers that most often are carrying laptops in their cabins.
Very important thing is that buttons of camera are very noisy (I noticed that also on Vantrue videos) - I silenced them with strips of sticky foam - just stuck measured strips in the gap between buttons and body edge. Its not perfect solution, but its the best what could do without opening the case (don't want to void guarantee).
I don't know how works ADAS in VanTrue, but in Junsun its useless. I know there are warnings on the screen, but its not safe to look on the screen when driving. So only way to make ADAS usable is to find way to switch sound warnings on.