I like the size and functionality. Some of its menus are extremely counterintuitive, and the manual is not much help. In particular, if you want to compose a novel text, the scrolling is tremendous as you travel from A to Z, one letter at a time. However, I was able to send text messages when I had no cell service, and that's what I wanted. Have not had to use the SOS feature yet, but anticipate that feature could be helpful. The Garmin interface actually seems to work well.
I have a RTL510. When I saw this product announced, I immediately ordered one. After seeing the DCRainmaker review, I changed my mind, as the video review and transfer is so slow and to be unworkable.
I did receive the RCT715 but sent it back. There are three issues.
1> It is bulky and heavy. It's about 1.5 times the size of the RTL510/515 (thicker and taller) and about twice as heavy.
2> It uses a different mount. This is a problem for me, since I already own the RTL510 and planned to use it as a backup on longer (60+ mile) rides when the main light ran out of battery.
3> I want to be able to retrieve video to make police reports about dangerous drivers. Based on the DCRainmaker review, I'm not sure I'm willing to put in the hours necessary to find and transfer the right video.
For the money, I think the RTL515 is a better investment.
Please take this for what it's worth. I don't think this is a good upgrade from the RTL series, but it still might be a good investment if you are starting from scratch and really want a radar/camera combo.
I bought this along with a Garmin 830 during their recent sale. I had heard great things about it both online and from members of our local bike club. Turned out to be one of the best purchases I've ever made. The thing just works. It has always been accurate even for multiple vehicles (it tracks up to 8 at a time). It makes riding so much easier by eliminating the constant looking over your shoulder. I do a lot of riding on rural roads and the Varia definitely keeps cars from sneaking up on me. If you have been thinking about getting one, just do it! You won't regret it.
I bought this when I recently purchased a Garmin 830 to upgrade from a simple Cateye computer. Pairing the sensor with the 830 was simple. Once it was paired, I manually entered my tire circumference for accuracy. The Garmin head unit uses that value to make the calculations in real time instead of using GPS resulting in immediate and accurate data. Going for my first ride with the Cateye as a comparison and a backup, both units showed the same speed and distance at all times. Satisfied with the results, I happily removed the Cateye from the bike for good. The best part about the sensor is that it goes around the hub; no more having a sensor on the fork and a magnet on a spoke. It's clean, elegant, and won't get bumped by accident. All in all, this is a great accessory for the Garmin units.