It looks like the update is about a week old. I'd never do such a young one. Wait a few weeks, keep checking the thread, and see if any problems develop. (The S3 4l.3 update took a few weeks to start showing problems, then turned out to be the worst update ever released.)
Also check other 4.3-to-4.4 update threads. If you use the SD card a lot, you may want to skip the update. (For instance, syncing a file from Google Drive to the SD card, then having another app write to it (say, to modify it) would be a problem, because only one of them can own the file. That's a 4.4 change.)