I have one of the Garmin varia radar lights and feel exactly the same about them.

> Where in the world do you live / where do you typically ride your bike? In what situations are you glad to have that radar?

UK; It's handy for knowing when on town or country roads without too much traffic; it can typically spot fast moving vehicles before you can hear or see them in mirrors (let alone if relying solely furtive glimpses over shoulder)

Tbh, nice as it is to be notified about approaching vehicles, what I really like is that the light flashes at proportionately faster rates in response to the speed of the approaching vehicles. The changing rate does a better job of attracting the attention of drivers than constant illumination, and is also a psychological hack that makes the driver think they are being watched [0] and consequently behave slightly better when they do pass.

Cumulatively the light/radar combination is a winner because it makes cycling more pleasant _and_ reduces the chances of getting hit by drivers.

[0] In some of the newer units they are being watched as well, as they have camera's in them - apparently unit is a bit chunky and video quality in low-light is ropey.

> video quality in low-light is ropey.

The video quality is ok.. ish. It’s not good in any lighting conditions but is plenty fine for getting licence plates etc.

The main issue for me is how hard it is to get it off the unit wirelessly. It’s slow and frequently loses connection.

Removing the card and doing it that way is better but the card is clearly not designed to be removed regularly and it would be very easy to break the slot that holds it.

> The changing rate does a better job of attracting the attention of drivers than constant illumination

Variable-time/Random bicycle light flashing is a pet peeve of mine: I find it much easier to track the location and velocity of cyclists when the frequency of flashing is constant.