>>Tell me if it's worth anything<<
That is a highly individualized assessment! My reasons for use are non-issues to others, so 'chaque a son gout!'
I have the Hoodman and love having it on the camera. Yes, you can swap out the plastic cover which is standard on the camera, and it apparently resists scratching reasonably, but greasy noses have to be wiped off the clear cover if you don't use the Hoodman. Just having the extra degree of protection will keep my camera body in Mint condition longer than if it does not have the Hoodman, and the protection to the body is more than a simple clear overlay affords to the LCD cover. It was a bit of disappointment in that it does not shade the LCD well enough to make things easily readable when shooting out in bright ambient sunlight, but not having to shade the LCD by hand quite so much to read it is nice.