Consider this a user assistance if you like, because I can't find any official help for Minecraft anywhere...

The new Simulation Distance setting doesn't seem to effect mobs. Friendly mobs at least (cows, sheep etc) disappear when you are more than 4 chunks away from them regardless of what you set this to, and I'm pretty sure they don't update (grow, move etc) I put a flashing redstone circuit behind them to test that that was updating still, and it was, that seems to work with the Simulation Distance setting as expected. All this testing was done between levels 70 and 90.

Is it intended that the Simulation Distance doesn't effect mobs and they always have an update radius of 4 chunks? If not, please fix , if so, can you please make it so they are? New mobs don't need to spawn, but I can't see the harm in continuing to update them. (also it just looks ugly them popping in and out so close)

Thanks! (p.s. is there any official help documentation that, for example, explains what the settings do etc?)