LivingEntity update frequency issues/questions

I'm having a hard time getting things right with my mobs and the update frequency of EntityRegistry.registerModEntity seems to be making the largest differences. This is what I have noticed in order.

With update frequency of 5, my mob would just move around very jerky.

[embed=425,349]

I changed the update frequency to 1, and they started moving smoothly, but wouldn't turn completely while moving so ended up moving diagonally. After they stopped moving, the body would turn back in place.

[embed=425,349]

I thought changing the update frequency to 3 fixed things since now they moved smoothly and straight, but they have an issue while they are leaping. They seem fine on the way up, but as they are falling down they seem to jerk up and down. I hope it isn't too hard to see.

[embed=425,349]

Changing the update frequency to 2  they still jerk up and down while falling a little, and they don't turn completely.

[embed=425,349]

Higher than 5 just made everything even more jerky. I guess I should also mention the rest of my registry values.

EntityRegistry.registerModEntity(EntityNightWraith.class, "NightWraith",0, this, 128, 3, false);

So as far as questions go:

1. What exactly is the update frequency and how do I know what I should set it to?

2. Is there something else that I could change that may fix some of these problems?

Thanks