https://www.kickstarter.com/projects/unawatch/meet-una-the-m...
so it's been out for less than a month. That's why you've seen zero reviews on websites, it's an indie Kickstarter. They don't have the marketing budget of a big wearables brand.
It has a GPS, IMU, and heart rate sensor: That's enough, obviously, to track activities, workouts, and health which their competitors do with the exact same set of sensors. It remains to be seen how accurate those are, or how well the manufacturer and community can develop useful algorithms to turn raw sensor data into activity logs and actionable health insights, but step 1 is to release an MVP to get people wearing the watch and logging data, and step 2 is to use the data to improve the algorithms.
The hardware seems top quality (looking past the waterproofing concerns, don't love that). On first blush it seems like its in the same league as my Garmin Fenix 6 Pro for tracking though, with obviously way fewer features at this point. I intend to do a side-by-side with the Fenix 6 and a heart rate strap to compare HR and GPS to see how it shakes out under tree cover and bouncing around, but the hardware seems up for it.
I see a single unboxing of the watch from three weeks ago on Youtube and zero reviews on YT or websites. Just posts based on their PR release that it's available now. (Though some clearly already shipped.)
Thus, it's unfortunately very likely that the product is also not good at its main purpose, tracking activities, workouts and health. If it would only even come somewhat close to the performance of all the competitor smartwatches/trackers, they'd be louder about that part.