I've had this 4802x for about 8 months now, fully updated to latest OS all the time. Nothing crazy in setup, etc. Mostly I stream Netflix and use a bluetooth headset, both from this 4802x.
Reboot Phase: Let's say I just rebooted the ultra. Things works great for a week or two. Then the bluetooth headset starts to randomly disconnect. Around this time too, playback gets hacked up, just randomly stops at some point in a show, counts up from 0% to whatever and restarts. I have zero bandwidth issues either. Lots of headroom with FireStick running in another room just perfectly. Bandwidth is clean (no drops - solid 20ms ICMP replies all Day long). Then as more time goes by both issues get more frequent and playbacks eventually stop/freeze and a reboot is the only way out (GoTo Reboot Phase: above, start over).
Basically there has to be memory leaks or similar software issues that are rather abundant. I've been around embedded systems and OS programming long enough to know bits and bytes aren't playing well together.
I hope this helps others. All I do now is wait for the first blowout, either bluetooth drop or playback fault and reboot immediately. My only pain is the minute or two it takes to restart and get back going again. is sucks, but OS memory issues are highly unlikely to be fixed any time soon. Content development I'm sure takes the cake. OS bugs, the crumbs.