I like how Simplify3D slows down the print towards the top of the model for finer detail.
You know what would be even nicer? If there was an option for it to also decrease layer thickness as it does that.
Particularly on organic models with a spherical finish towards the top, the layer thickness becomes very obvious in the form of conspicuous concentric rings. If the software automatically reduced layer thickness for finer detail towards the top, I think this effect can be minimized in a fairly seamless manner. Just put more detail where it's needed.
The implementation would have to be the top x layers of every island though, not just the very top of the model. It would likely also need to be a gradation of layer heights not just a simple binary switch to 50% thickness. Might make things a little complicated because then the nozzle would need to jump layer heights in scenarios where 1 island is printing at a 0.1 standard thickness and another island needs to go down to say 0.8. If nozzle lift doesn't cause issues with retraction I would assume this could be done also.