C4D had the reflection channel replaced by the reflectance channel in R16. So, it is not new. It could be “new to you”, if you shy away from using it to its full potential. That’s not an uncommon occurrence because of the amount of attributes in that channel. It can be a little confusing.
If you don’t know what sliders you should and shouldn’t be using, this is a tutorial for you. 3D Fluff has a look into simplifying the C4D Reflectance Channel, showing a process for achieving the look you are trying to get. When overcome by a UI, its best to do things systematically!