I've only handled two kings regularly...a florida king that was about 3 feet long and was a dream to handle. He was very calm, laid back, and the sweetest little guy I've ever met. He's what prompted me to buy my little rascal (a young cal. king). My guy was pretty friendly upon initial handling, but has become somewhat wild.
I think my problem is that he's in such a large cage that he buries himself where it's difficult to find him. So I'm having to dig up all the substrate and decor in my hunt for him. As you can expect, this ticks him off a little and he gets defensive. He strikes out and will bite (though it doesn't hurt and he draws no blood) and is quite adapt at musking me when first picked up. When he's been held for a while (10 minutes), he calms down and is really good, but if I move too fast he flips out. I think with regular handling and some age, he will calm down. From what I've been reading, it's not uncommon for baby kings to be easily startled and ticked off. Once I realized the bites were painless and stopped pulling away, he backed off on striking at me.
He's a great eater and gets a dethawed pinky every 4 days. I haven't had any trouble feeding him as of yet.