the new 4.3 bootloaders lock things down a bit, you can still root so no worries there just it blows a qfuse and anyone who looks in download mode will know you rooted. there will be no triangle away to cove rit up or anything.
once you flash that bootloader another qfuse is blown in that you cant downgrade, you can flash 4.3 odin tar all day long but cant go to 4.2 bootloaders. you can however stay on 4.2 and flash a rom from 4.3.someone who updates, doesnt care for warranty etc can just do teh ota and root and then dump all the files needed for everyone else to update
just wanted to clear some things up before ota hits and some people find themselves in a pickle.