Purchased the device a few weeks ago. It looks simple but elegant. Initially, I had issues with Bluetooth connectivity. But after e-mailing customer service, it was resolved by re-installing the app. I have been using it everyday now. A lot of basic sleep data are provided but can't tell for sure how accurate this technology is since I don't have other sleeping ring data to compare to. However, the data somewhat do reflect usually how bad or good I slept. Sleep areas that need attention is what interest me the most. On the overall, I am happy with the purchase & will continue to use the device.