I like this device for the heart rate monitor functions but after upgrading it last week it got bricked. During the upgrade it hanged for several hours, after restarting the app, it cannot connect to the device again. Fortunately I was able to return and got a replacement.
An updated app just came out which is suppose to fix this issue. I was about to take a chance but the upgrade page looks incomplete, it does not know what firmware my device has and it does not show what firmware it is going to upgrade it to...so I cancelled the upgrade process.
I would have rated this a 5 star before the upgrade but now it is a 1 star until there is proof that an upgrade is successful for the new firmware with sleep monitoring functions.
If anyone has successfully upgraded there device to the latest firmware with sleep monitor functions please let us know.
Knockout777 about Mio GO, v2.6.1