My setup is to: Dock the content browser in the layout. Create a new folder on my harddrive called "A B Renders". Then add this folder to the content browser "favorites" by right clicking on this folder from inside the content browser and selecting the "Add to favorites".
My workflow is as follows:
I render an image in Cinema 4D or Maxwell Render. Save the image to the "A B Renders" folder. Then view this folder in the content browser where I can pretty much just click between two or more renders and use the preview area as the switching region.
It works quite well, and fills the need for A/B Render image feature. Although I would like to have more than one "Picture Viewer" window in Cinema 4D.
Image: Although this image is used for explaining something else, it does however contain the content browser being used in the manner I have described above. And it works very well in this function.