Quote from the 4.4 RC 1 Changelog:
Originally Posted by saumil007
4.4 RC1 - Kitkat 4.4.3
Dose of awesome sauce on this week from PA Headquarters, again. As you may know we merged 4.4.3 into our source. You will need to flash new bootloader, radio, Gapps and update to latest recovery before going forward. Many bugs have been also resolved on our bug tracker thanks to community’s reports, less to go.
In the changelog for 4.4 RC 1, we are told that we need to flash a new bootloader and radio. This has not been part of my normal process. Why do we need to do this? Also, I wasn't able to find any threads on suggested bootloaders and radios for PA. Please point me in the right direction if this is something I really need to do. (using a Nexus 5)