Samsung Galaxy S4 rooted on 4.2.2. Considering unroot to load 4.4 Kit Kat. Worth it or not?

[AC Question]

SGH-I337 on At&t. I am not interested in custom ROMs. My phone is fine but I am concerned the old software will eventually cause issues with apps. If I am going to update, I think it should be now before the Lollipop update rolls out for the S4 on ATT.

Also, is there an easier way to update to the Kit Kat as is or do I need to un-root first, update, and then re-root? Thanks!