Although canon does not have a way to load an external "picture styel" or "curve", the styles are actually quite useful. Admittedly, I have not figured them all out in detail (and probably won't). However, the basic ability to modify and existing styles and to create your own user defined styles allows you to effectively create custom curves that modify sharpness, constrast, saturation and tone - all in one menu location. IMO, this is better than having sharpness, contrast, saturation and tone in different menu selections.
If you set up your one or two (or many) personally needed styles, you can select amongst them quickly without changing any other camera operational parameters. This is a darn'ed site better than assigning each "curve/style" to a profile which records most operating parameters.
In my case, I have user defined styles that are set for theatre/dance performances, outdoor sports/events, low contrast subjects - all of which are based upon "Neutral".