First off, learn to 'see' in b&w. Spending hours in front of a monitor clicking on image after image in the hopes that an image will suddenly jump out and and be an award-winner is a
huge waste of time. So you should only be working with images that you know
beforehand have a chance of becoming monochrome masterpieces. I rarely 'see' a black and white for the first time in post.... 99.99% of mine are 'seen' before I even pick up the camera.
Another thing is to learn to cull your tens of thousands of shots down to what you want to edit. No need to edit
everything.... just what is worthy of editing needs to be dealt with. This is easily done by star rating your images during initial ingestion. Then you can set your editor to only show you the 1+ star-rated images.
Now that you're down to a managable number, Nikkon's NX-D will easily compare two images side by side. Just open the folder, select the image, then click on the "Side by Side" icon (red arrow). Change one image to monochrome (green arrow).