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.
This Edge 840 is a very good upgrade to the Edge 520 it replaces. I've ridden with it for over a month and have these observations.
- Battery life is greatly improved, with many more rides between charges.
- Display is larger on a similar sized device, permitting more stats while maintaining readability.
- Touch screen controls easier to navigate than buttons, especially during a ride.
- Improved map details, which includes road and traffic alerts.
- Fewer false incident detection for urban riders. Much of my ride is in urban landscape, with rapid stops that triggered incident detection on the Edge 520.