I installed 5.0.0.348 about 7 hours ago and it is great! I have have not had a single reboot issue. All my apps installed clean and they are working perfectly. I previously had 5.0.0.314 installed and it was good as well, except for all the random reboots.
Upgraded to 5.0.0.348 yesterday. It was my first time ever upgrading my OS. No problems at all. No rebooting issue. The only thing I noticed was my weather icon appeared as a blank white square after install. But after a short time it went back to normal. Other than that it's great! I love all the new options. I was pretty hesitant at first to upgrade and thought that I would wait for an official release but I couldn't wait. I just went the the upgrade/downgrade 101 tutorial step by step and everything went smoothly.