I found an article on why we should use 16-bit mode as opposed to 8-bit when working with images. Working in higher resolutions has always been a good idea when using filters and effects. The more pixels you have to play around with the better.
16-bit follows the same logic. Same amount of pixels, but more information per pixel. The added color data gives you more control over subtle differences in color. The difference may not be perceivable by many, but the overall mage quality in the end might be better. The final product need not be in 16-bit. 8-bit should be able to capture the results of filters, effects, and subtle maniputlation. It is when working with the image that you need 16-bit.
I guess its like starting out with 100lbs of clay and finishing with 5lbs. The end product may or may not be better than if you started with 5lbs. Eh?