I am going to assume by this statement that there are a lot more fixes or enhancemnts than what is listed in the orig post.
Correct. Reboots are no longer seen in automated stress testing, bench testing, or the Field Trial.
The system will still reboot automatically (to keep you from having to get off the couch to Front Panel reset it) if an error is detected. As with all software, I'm sure there are still ways to "crash" it and get it to reboot. If you find such a way, my advice is to let us know and then stop doing that.
For those seeing instability immediately following the download, remember that the receiver is like a computer. When you first log into Windows, your computer usually runs at its slowest. It's starting processes, installing updates, verifying files, etc. If you hammer on it during this time, it's usually pretty easy to lock it up.
Give the receiver a chance to complete the post-upgrade migration and file and database verification. It's also reloading Guide data at the same time, adding to the load. The same goes immediately following a reboot.
Beyond this, if you're still having problems, we're now in a position to look beyond the software as the cause of the issue. We'd initiate troubleshooting and run through everything to try and find the source of the issue and get it resolved for you.