I got these for road cycling, but I ended up using them mostly for running, because that's where they shine (and as the name implies, that's mostly what they are for). I pair them to my Garmin while running and have zero complaints. They are excellent. I do also using them riding, but obviously they are open ear headphones and if you have any significant wind noise you will have to crank the volume to get decent audio, which defeats the purpose because you can't hear what's around you. I can't wait to try these while mountain biking when it gets cooler, because I bet they will be outstanding at those slower speeds. They are also great for longer road climbs and you can just deal with the wind noise on the way down.
I'm not familiar with other, similar units ' although there are a few. I purchased this because of my experience with other Garmin products' and it was on sale! So far, I've not been disappointed as it does everything I'd hoped for. One thing I've noticed is that if using the screen on your phone, the traffic icons are spot on' as opposed to shutting the screen off and relying on the audio alert only: in this case, there could be two cars when you're expecting only one. That said, I still use my mirror to be sure. I also like the fact that you're given plenty of time before traffic comes near you' just in case you need to do some emergency maneuvering. If you're curious about radars, definitely check this one out!
BTW: I use an IPhone 12 with the Garmin Varia app. I understand it will also work with Ride with GPS, but I haven't tried that as yet.
This is my second Varia, bought for a bike I have in a different location. I've been using the first one for about three years now, and it is terrific. The new one is the same. The light itself is very bright, and the radar works well close to 100% of the time, even most of the time when riding in a paceline, but that is the occasional time when it won't pick up an approaching car because of interference from the back of the pack. Its range is excellent, picking up an approaching vehicle from about 1/4 mile back. Highly recommend.
Definitely an improvement from older Edges! Much clearer screen and much faster. Much nicer software to set profiles. Just nicer to set and control options. And one friend noted how nice the new sound was with my radar light. Still, there's lots of stuff I'll never use, though I'm sure some people will. And then there are the warnings about an animal ahead, and I wonder when that was seen. It was a splurge, even on sale, but I am enjoying it.