VFM compared to other well-known brands that have similar products. I've had it since summer and have done over 1,500 km, and I have no complaints. I've used it for 5 hours straight—150 km—without the battery causing any problems (I don't think it dropped below 40% on that ride). With some vans/larger vehicles, it may get confused and show that two vehicles are approaching together. This isn't a problem because it doesn't change anything in practice. It would be bad if it failed to detect a car or motorbike approaching, but that hasn't happened in my experience so far. I consider a bike radar an ESSENTIAL accessory, not a luxury or something for specific situations. It really will cut your anxiety in half when you're out on any road. You can never be completely relaxed and confident, but with an accessory like this, you have a serious ally.

Check whether your bike computer device generally supports radar. I use it with a bike computer app on my phone (it's called Cadence). You can see it in action in a video I recorded here:
https://youtu.be/-1OaIM_xu3A?t=681
Note: It's the bar that appears along the left side of the screen. Green when nobody is approaching, yellow when it detects a car (from 160 m away). Red when the vehicle is moving at over 80 km/h relative to you. The vehicle(s) appear as a graphic that moves along the bar and can be seen as they approach. The graphic reaches the very top of the screen when they are beside you. All of the above can be customized (colors, speeds, etc.)