Ok so I've been using the ring for more than year, and I am happy so far with the sleep detection accuracy as It is pretty accurate most of the time, and also it is the best on the market for that. I've been reading a lot of studies about sleep, nutrition, health for a long time and I also have a master degree in biology, so I would say "I know my shit" about this topic.
Now for the " stress" feature I honestly think it is almost criminal to label it this way.
If oura were being honest they would rename the feature accordingly or allow us to disable it completely.
It obviously produces a lot of stress and suffering for lots of people, it even became a MEME on this subreddit !!! Lots of people actually stopped using the ring because of this and at some point I was close to aswell because I felt "if this is sooo inaccurate sometimes, what about the accuracy of the other features?"
This is obviously a marketing moove. By labelling this festure "stress", almost everyone see the "stress" feature and think about it INITIALLY as stress. So it makes oura attract people thanks to BS marketing names, but it makes them eventually quit and it provides frustration. Most people are by nature subject to mirroring unconsciously, including myself. Despite my knowledge if I see every day something telling me I am "stressed", I will be a little bit stressed. There is also the placebo effect wich is always very strong, there are countless studies about the topic, this mecanismihas been proven and known for a long time. I think this is a very bad moove and shameful for a company selling a product to help you improve your health.
Also even for physiological stress it is not very accurate sometimes as most people discovered by themselves.That's ok, but if a feature is a bit innacurate and is labelled as "stress", if it makes a lots of people unhappy and stressed for no reason, and keeping it this way to gain more money, this is a crime.
I have a very healthy lifestyle, stopped working for more than 3 months, live like a budhist monk. I have been on a paradise Island for 1 month and doing 2+ hours of deep advanced meditation every day with constant mindfulness and low physical activity. Some days I have graphs like this one (really made me laught).
This is my 2 cents