Ok, I do not ordinarily write reviews unless I am very impressed and this sleeping mat really impressed me. I have tried a variety of sleeping mats/sensors in the past and the single biggest problem with them all (other than this one) is that they require you to use your phone to record the sleeping data. With other mats, you need to remember to open an app on the phone and you need to store all the data on your phone, which gets very annoying after a short while. Not with this mat, the sleeping mat communicates with Withings directly over wifi and all your sleeping data is stored on their website. Your phone is just used to view the data whenever you want, you can delete the withing app from your phone and it will not erase the data. The other important thing about a sleeping sensor is the accuracy, a sleeping mat/sensor is no good if it is not accurate, and this one is meeting my accuracy standards. You do need to be careful where to put the sensor (they say under the sternum) but once you do that, then you don't need to worry about placement ever again, or even need to think about the sensor ever again. It just records your sleep every day without you ever having to think about it. This point is not to be under estimated, I have 10 years of daily weight data stored on the Withings website, because I use their weighing scale. And no, I am not giving them 5 stars just because I own their weighing scale, I would simply not bother writing a review if I was not truly impressed with the product. I am going to come back and update this review after 1 year, the true value of a good sleeping sensor is in being able to consistently produce a good measurement every day. Update after 1 month: 1. Robust: I have used it for a little bit less than 1 month now, and I have a reading from every day. This is a first for me, my previous sleeping sensors never made it so far. 2. Accuracy: Accuracy is not super good but not super bad either. If you lie still in bed and do not move, this sensor will put you down as "REM", and the other deeper sleep settings can be fooled too. I think i have to leave the bed or sit upright for it to think that i am awake, otherwise it thinks that i am asleep. If the sensor is able to measure my heartrate and i don't move much, it has me down as asleep. Not complaining to be honest, I am not sure how much better someone else can do either. 3. Speedy reading: Typically i get the results as soon as i get out of bed, within 5 mins. On a few occasions, it has take longer. Sometimes as long as 6 hours. I think the sensor tries to connect to the website, if it is not able to connect, waits for a few hours before retrying. Not sure exactly what happens in the few instances. But I have always managed to finally get a reading from the previous night, even with those delayed instances. I see a lot of negative reviews and I feel that this could be a cause of concern. When you don't see the results right away, you get nervous that the sensor could be broken. 4. Five Stars: Yes, I still give this product 5 stars despite everything. Competitors take note, this is the first time that a sleeping sensor has been able to track my sleep for as long as a month, and the data is stored safely in Withings website. I don't think any other sleeping sensor competitor can say they do as good a job, including the mighty Apple. I am afraid that making a good sleeping sensor is so hard, that people might simply think it is not worth the effort.
