Some of the highlights of what Corona Renderer brings to Cinema 4D:

• Interactive Rendering, to make test renders a thing of the past
• LightMix, to change color and intensity of lights before, during or after rendering
• the Corona Node Material Editor, to make creating materials easier than ever (any version of Cinema 4D supported by Corona Renderer)
• Denoising (CPU, and GPU if you have a compatible NVIDIA GPU)
• Tight integration with Cinema 4D
• Compatibility with many native Cinema 4D lights and materials
• Compatibility with Team Render

Read full details about all the above, plus everything else there isn't space to mention, over in the blog post.